Best heads for 500hp?
I’ve went through the rabbit hole of the ls1. 225heads. 11:1. Big cam lotsa overlap. Later slapped a procharger and meth on it. Made even more power eventually I was running 12-14lbs. I was beyond the dependable limits of SBE and without meth it would blow up lmao. Later swapped cam to a billet custom grind from Martin Smallwood, Johnson link bar lifters. Custom manton pushrods. Loped about the same but was way more drivable and easier on the springs..I think 228/244 .612/.612 113+3. Made even more power on the same pulley. Now have a turbo 5.3 which by and large is too fast to even drive and spins 15” et street r tires at 100mph. Both cars were 6 speeds and from first hand xp skip the fast 102 and crazy ported head bs, for the money the gains just aren’t there when you could have boosted it for about 4-5k and made more way more than you could dream of NA. I’m not flaming anyone but people claiming 500wheel NA on a SBE unopened ls and baby cam are smoking some good stuff or not telling you secrets and they are ringing it out to 7500 or something lol, if it was easily repeatable you wouldn’t see so many 450-480 all out builds..that’s your 99.9% of times the typical big cam, nice heads, and intake for a SBE ls1. Shop around. I got my procharger kit for about $4,000. Get an okay set of heads and a decent driving cam and procharge it. Without a doubt hands down the procharger car was way more fun to drive and made for a much better street rod, even though it definitely was slower than my turbo, there’s something about hearing a jet engine singing at stoplights and the race bypass opening on shifts etc. I’d go back in a heartbeat if I could. I regret selling that car.
Last edited by mstansbury0704; Dec 7, 2025 at 09:05 AM.
I never had belt slip issues. I did run the newer procharger spring loaded bracket from brute speed. Never ran the 6 rib setup but 8 rib and I’d have to go through my receipts but I ran the bigger pulleys. I had to Dremel a hole in all of the shoulders except my 12-14lb pulley because you couldn’t get your Allen key into it to put the last upper procharger mount bolt into the bracket. I didn’t run the big crank pulley. Whatever the typical 8 rib crank pulley size was is what I ran. Only had belt dust issues when my belt actually needed replaced. D1SC
I never had belt slip issues. I did run the newer procharger spring loaded bracket from brute speed. Never ran the 6 rib setup but 8 rib and I’d have to go through my receipts but I ran the bigger pulleys. I had to Dremel a hole in all of the shoulders except my 12-14lb pulley because you couldn’t get your Allen key into it to put the last upper procharger mount bolt into the bracket. I didn’t run the big crank pulley. Whatever the typical 8 rib crank pulley size was is what I ran. Only had belt dust issues when my belt actually needed replaced. D1SC
Well I do have a hard time buying into the 500rwhp from a 346 when I know what's in my LSX427 and I'm pushing 540-550rwhp from Pat G's Mustang dyno. I have not put the 370 on the dyno yet but that's a 12.5:1 motor that has a start up tune for MS109, it has a smaller camshaft than the 427, transmission is a Powerglide and it has an aluminum driveshaft and a MWC Fab 9, now I'd be happy to see 500rwhp on the dyno but I have my doubts because well I built a 427 that's making over 630fwhp.
I had that ls set to a 7k limiter when it was at 10-12 lbs and shifted on the chip lol. I upped the boost but shifted it around 67ish but often would hit the spark cut in lower gears. In good air it would make 14lbs on the limiter. Map rise was pretty linear in my logs.. but I never power shifted it or anything super crazy. That procharger spring bracket is pretty damn stout. It felt about 3x as hard to move as the factory belt tensioner.
You try and tell me that your making 500rwhp naturally aspirated from a 346 with 12:1 on 93 octane and I'm going to ask WTF are you smoking? Making a 10 second pass from 346 I'll buy all day everyday because there's so much more that goes into it other than the engine. There's been countless Fbody cars with untouched bottom end LS1's that have reached 10 and I know of one and what all he did to get there and that was a lot of weight reduction with some work up top and he was a little big guy if you know what I mean.
Yea idc about trap speeds or dyno numbers alone. Show me an 11 second f body and I’ll show you a corvette I can wedge that exact same power plant in and run 10s. Meanwhile I’m driving around with 200lbs of landscaping block in my t top well just so I can play around on the interstate LOL.
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You try and tell me that your making 500rwhp naturally aspirated from a 346 with 12:1 on 93 octane and I'm going to ask WTF are you smoking? Making a 10 second pass from 346 I'll buy all day everyday because there's so much more that goes into it other than the engine. There's been countless Fbody cars with untouched bottom end LS1's that have reached 10 and I know of one and what all he did to get there and that was a lot of weight reduction with some work up top and he was a little big guy if you know what I mean.
I'm not the only one who has done it. The used cam in my combo did it in another combo. And by today's standard it's not that big. 23x 24x range like everyone in this thread is talking.
Through a 9" and exhaust out the back. Didn't even pull the air cleaner.....that typically makes more......dumps would likely make more. E85 would make more . Bypass the ps would make more.
Realistically 600whp out of a 5.7 isn't out of the question.
The record for the fastest sbe 5.7 is 9.2......it likely made more than mine.
My 5.7 isn't really sbe tho. Although not far from it. Basic rebuild with gen4 rods and off the return shelf mahle pistons. Stock crank ofcourse.
As I always said. If my bolt on ls6 can make 451whp 423wtq and your average h/c ls1 can't make atleast that and realistically more......then you did it wrong. Not the engine......but you.
Maybe because they're all Dynojets? How about guys who compare a Mustang dyno to a Dynojet? Again, it really doesnt matter. Theyre a tuning device, NOT invented for racing one dyno's results against another. I've gotten my numbers on a Mustang dyno, the same one I've always used, with the same tuner. When the numbers go up after a mod=success. I couldn't care less what another guys numbers are, because it's not my car, and I didn't pay for the tune. Trap speeds shouldn't vary if you factor in DA. Trap speeds, at least IMHO, are what matters when discussing horsepower. I've never beaten, or lost to, a dyno. To each their own....
Most on here would be wondering what cam it needed......or the greatest newest baddest heads to put on it.......while still not trapping what stock **** did🤣🤣
trap speeds can very greatly. First time I ran my ls6 it trapped like 118.......same identical engine but with a few different parts/ developing around it and it trapped a best of 131.3. Not even much power difference at peak. About 10-15 whp.......but gobs of tq in the middle. Funny part is after trapping that and playing with it some more it picked up 34whp and nearly 30wtq more. It probably had a 133+ trap in it i just didn't get to run it again.
Most on here would be wondering what cam it needed......or the greatest newest baddest heads to put on it.......while still not trapping what stock **** did🤣🤣
Most on here would be wondering what cam it needed......or the greatest newest baddest heads to put on it.......while still not trapping what stock **** did🤣🤣
Hell, mine with the fast 102, ls2 tb, tea stage 2 243s still made 470/420 with less than stock compression. If I would have ran a thinner gasket, flycut the pistons and really honed in on that combo, it could have made 500 easily. I did really not much work to make another 35-40 wheel out of it going to the tfs 220s, hi ram and johnsons with a thinner gasket. The most work was cutting the hood haha
Just to throw in my 2 cents. I agree that it's going to be cheaper and more street friendly to go forced induction over NA.
I recently bought a 2010 Camaro from the Camaro5 forums, and it is 530whp NA. It has a GPI Max Performance package on it, which is small bore LS7 heads, LS7 manifold, and camshaft 238/256 .648"/.639" 113+4. Also has other supporting mods. Trying to re-create this setup (just the heads/cam/intake/lifters package) is about $7k. Driving it around town is fine, but if you get stuck in stop and go traffic it's not very fun - it is a M6 with a twin disk clutch. It's driveable, but doing constant starts and not getting to release the clutch fully before having to stop again, over and over, is not very fun and makes me worry about overheating the brand new clutch I just put in. As a side note, it has 20k miles on the package, and I currently have it down for changing out the lifters, one of the Johnson 2110R lifters went bad already - high lift cams require high pressure springs which put extra load on the entire valve train.
Getting the Cam, Heads, and Intake all to work together is the most important thing when trying to make power NA.
I recently bought a 2010 Camaro from the Camaro5 forums, and it is 530whp NA. It has a GPI Max Performance package on it, which is small bore LS7 heads, LS7 manifold, and camshaft 238/256 .648"/.639" 113+4. Also has other supporting mods. Trying to re-create this setup (just the heads/cam/intake/lifters package) is about $7k. Driving it around town is fine, but if you get stuck in stop and go traffic it's not very fun - it is a M6 with a twin disk clutch. It's driveable, but doing constant starts and not getting to release the clutch fully before having to stop again, over and over, is not very fun and makes me worry about overheating the brand new clutch I just put in. As a side note, it has 20k miles on the package, and I currently have it down for changing out the lifters, one of the Johnson 2110R lifters went bad already - high lift cams require high pressure springs which put extra load on the entire valve train.
Getting the Cam, Heads, and Intake all to work together is the most important thing when trying to make power NA.
Yea......most want to throw a 8k rpm stage 52 cam in something, use a stock intake ( especially on a ls3) and then not up the compression.
Then wonder why their combo is slow and pick a bigger cam to fix it.
Btw....we made as much as 470whp 470wtq with a bolt on ls3. That was in a 5gen. With a bolt on ls3 in a c6 we went 10.5@132......not gutted and through the oe npp mufflers. I bet if someone was serious a bolt on ls3 in a c6 could touch the 9s.
yea we did a build back in the mid/early 2000s that made 45x whp.....thought is was great. Very simple gmpp cnc 243s the milled .055 versions. Gmpp grand am cup cam. Mild rebuild on the bottom end cause it was smoking. Used je pistons.
Today that same combo with some minor changes could easily make over 500whp. We had a ls6 intake on it......because back then that was all that was really available. I bet a ported msd would have picked it up 30whp. Had no ewp so there's another 10 especially with the belt mod I do....maybe even a little more. The pistons were poop....heavy *** je with thick rings. A set of mahle power pack pistons are way better. It had poopy Mac mid length headers and some home made exhaust. Se headers and td x would be a massive improvement.....which is what's on my car now except the headers are kooks. No crank scraper and pump gas......that's why i said one can get 500whp out of a 5.7 without leaving the gmpp parts catalog.
It seems many of these guys are stuck thinking they did the ultimate best job and picked all the right **** without thinking about what they actually did or evolving with the times.........then they cop a attitude.
They stuck at 6500 rpm for some reason too. My bolt on ls6 got turned up to 7200......this 5.7 turns 7800. No crazy valvesprings on it. Just some thought put into it.
Then wonder why their combo is slow and pick a bigger cam to fix it.
Btw....we made as much as 470whp 470wtq with a bolt on ls3. That was in a 5gen. With a bolt on ls3 in a c6 we went 10.5@132......not gutted and through the oe npp mufflers. I bet if someone was serious a bolt on ls3 in a c6 could touch the 9s.
It really isn't that hard, but so many are still stuck in the "need 400+ cubes to make 500+whp" club.
Hell, mine with the fast 102, ls2 tb, tea stage 2 243s still made 470/420 with less than stock compression. If I would have ran a thinner gasket, flycut the pistons and really honed in on that combo, it could have made 500 easily. I did really not much work to make another 35-40 wheel out of it going to the tfs 220s, hi ram and johnsons with a thinner gasket. The most work was cutting the hood haha
Hell, mine with the fast 102, ls2 tb, tea stage 2 243s still made 470/420 with less than stock compression. If I would have ran a thinner gasket, flycut the pistons and really honed in on that combo, it could have made 500 easily. I did really not much work to make another 35-40 wheel out of it going to the tfs 220s, hi ram and johnsons with a thinner gasket. The most work was cutting the hood haha
Today that same combo with some minor changes could easily make over 500whp. We had a ls6 intake on it......because back then that was all that was really available. I bet a ported msd would have picked it up 30whp. Had no ewp so there's another 10 especially with the belt mod I do....maybe even a little more. The pistons were poop....heavy *** je with thick rings. A set of mahle power pack pistons are way better. It had poopy Mac mid length headers and some home made exhaust. Se headers and td x would be a massive improvement.....which is what's on my car now except the headers are kooks. No crank scraper and pump gas......that's why i said one can get 500whp out of a 5.7 without leaving the gmpp parts catalog.
It seems many of these guys are stuck thinking they did the ultimate best job and picked all the right **** without thinking about what they actually did or evolving with the times.........then they cop a attitude.
They stuck at 6500 rpm for some reason too. My bolt on ls6 got turned up to 7200......this 5.7 turns 7800. No crazy valvesprings on it. Just some thought put into it.
Last edited by HioSSilver; Dec 8, 2025 at 10:12 AM.
trap speeds can very greatly. First time I ran my ls6 it trapped like 118.......same identical engine but with a few different parts/ developing around it and it trapped a best of 131.3. Not even much power difference at peak. About 10-15 whp.......but gobs of tq in the middle. Funny part is after trapping that and playing with it some more it picked up 34whp and nearly 30wtq more. It probably had a 133+ trap in it i just didn't get to run it again.
Most on here would be wondering what cam it needed......or the greatest newest baddest heads to put on it.......while still not trapping what stock **** did🤣🤣
Most on here would be wondering what cam it needed......or the greatest newest baddest heads to put on it.......while still not trapping what stock **** did🤣🤣
Last edited by grinder11; Dec 8, 2025 at 10:59 AM.
[QUOTE=wannafbody;20632992] I agree with you 100%....
That may be true. But who cares about high dyno numbers? Theyre for tuning, nothing more, nothing less. A 400whp number on dyno A might make 425+whp on dyno B. Let’s say you're racing someone stoplight to stoplight, and you're dead even until you hit 2nd gear. Then your 10 bolt blows, if the winner comes back to try to help, which I doubt, most of us aren't going to say "Ill bet my car will make more power on the dyno than yours will." To which I'd reply "Not right now it won't!"[/QUOTE
My comment wasn't aimed at HioSSilver. It's more about people who think inflated dyno numbers mean there car is faster than someone's car that puts down lower numbers. Through the years I've seen people claim a cam only 5.7 puts down 450 hp. Maybe their dyno slip says so or maybe they are just full of it. It's amusing nontheless.
I'm not really aware of a lot of people running over 11:1 compression on a daily driver type of 4th gen. Sure cranking up the compression can make power but is it going to hurt the engine long term in hot and humid conditions?
My comment wasn't aimed at HioSSilver. It's more about people who think inflated dyno numbers mean there car is faster than someone's car that puts down lower numbers. Through the years I've seen people claim a cam only 5.7 puts down 450 hp. Maybe their dyno slip says so or maybe they are just full of it. It's amusing nontheless.
I'm not really aware of a lot of people running over 11:1 compression on a daily driver type of 4th gen. Sure cranking up the compression can make power but is it going to hurt the engine long term in hot and humid conditions?
Hio, you stated in post 51 (?) that "one fella on here went 10.0@135 with a bolton LS6. I call TOTAL BULLSHIT. Unless the bolton was a blower or turbo, there's no way I'll buy that. Maybe you buy it, but I don't. Some might drink that Kool-Aid, not me!! Total BS. It seems you associate with some of the quickest, fastest stock internals LS6 powered cars known to man here on earth. Whatever.....I got better things to do. After I saw post 51, now I've heard it all......
I dont know what "parts developing around it" means. But you got a bum reading on a 131mph trap speed on an LS6. THATS a good 4-6mph faster than a 427 LS7 puts down!!! There's no stock internals LS6 on the planet thats run a bonafide 131mph in the 1/4 mile!! Unless the strip was running downhill@a 5° angle, with hurricane Michael as a tail wind. It would take major parts changes and major investments to run 131mph 1/4 mile trap speeds. Trap speeds have long been a legitimate way to determine power. I know any bike or car that I ever owned and raced ran consistent trap speeds, unless I made a rather significant change. If you run 115mph trap speeds on a 500' DA one week, if you race the next week and DA is still about 500', your trap speeds is still gonna be around 115mph.
Hio, you stated in post 51 (?) that "one fella on here went 10.0@135 with a bolton LS6. I call TOTAL BULLSHIT. Unless the bolton was a blower or turbo, there's no way I'll buy that. Maybe you buy it, but I don't. Some might drink that Kool-Aid, not me!! Total BS. It seems you associate with some of the quickest, fastest stock internals LS6 powered cars known to man here on earth. Whatever.....I got better things to do. After I saw post 51, now I've heard it all......
It's funny you would do that tho.....I went 131.3 and can clearly see how he went 135.......I guess you either know or you call bs.
You call bs because you don’t know.
So more displacement with bigger/better flowing heads makes no more power on 93 octane than a basic bolt on LS1 with some mild worked over cathedral heads. Got it!
I just cannot see a 3.898 bore utilizing cathedral heads originally designed for the smaller bore making more horespower and torque than a 4.125 or larger bore using LS3 or LS7 heads with a similar camshaft.
I know we won't get any factual evidence and that's okay!
I just cannot see a 3.898 bore utilizing cathedral heads originally designed for the smaller bore making more horespower and torque than a 4.125 or larger bore using LS3 or LS7 heads with a similar camshaft.
I know we won't get any factual evidence and that's okay!
@2000Phoenix have you decided your plan? Is the car stick? Apologies if you already answered these questions. 
I had a 2000 Camaro, 5.7 flat tops, TFS 215s out of the box, LS2 intake, auto T400 trans, 4.10 9", light, and it went 10.92@123 and it was actually set up for nitrous. It made 42x rwhp unlocked on a Dynojet. This was 18 years ago.
I had a 2000 Camaro, 5.7 flat tops, TFS 215s out of the box, LS2 intake, auto T400 trans, 4.10 9", light, and it went 10.92@123 and it was actually set up for nitrous. It made 42x rwhp unlocked on a Dynojet. This was 18 years ago.
@2000Phoenix have you decided your plan? Is the car stick? Apologies if you already answered these questions.
I had a 2000 Camaro, 5.7 flat tops, TFS 215s out of the box, LS2 intake, auto T400 trans, 4.10 9", light, and it went 10.92@123 and it was actually set up for nitrous. It made 42x rwhp unlocked on a Dynojet. This was 18 years ago.
I had a 2000 Camaro, 5.7 flat tops, TFS 215s out of the box, LS2 intake, auto T400 trans, 4.10 9", light, and it went 10.92@123 and it was actually set up for nitrous. It made 42x rwhp unlocked on a Dynojet. This was 18 years ago.
My car made 408 rwhp with a 227/234 cam, ported 243 10.5:1 compression, M6, DLS2 intake. I probably picked up a couple HP when I upgraded the exhaust. Open the cutout and I get maybe another 10 or so.
Last edited by wannafbody; Dec 8, 2025 at 06:01 PM.