looking to add heads to my car. car has a unknown grind from previous owner with supporting mods listed and 4:10 gear rear end car put down 398 hp.....my question how to go about choosing heads......start over with new cam or try to match this cam

 

Welcome to the forums.

Personally, I would ditch the comp cam out of principle and start with something you know. Get one of the vendors on this site to spec you something specifically for your combination of parts and how you want to drive your car.

Surprising that BBK intake beat the LS6 intake in HotRod Magazine's 20 intake test, which is neat. And you already have 1-7/8" headers.

As for heads, are you wanting to get your current castings ported or buy fresh heads entirely?

If you have 241's and want to get them ported, then contact Phil @ Advanced Inductions for his 219cc High Compression program, and have him spec you a cam at the same time.

If you want new heads, then you cannot go wrong with TFS 220 Fast as Cast touched up by Brian Tooley, and you can get one of his cams at the same time.

 

looking at new heads all together, as far as cam I was leaning towards the torque v4 or sns stage two

 

I would assume that since you made almost 400 to the wheels, the cam in the car is decently sized. I would keep the cam and run some ported 243s from ai or tea, or if you didn't want to get castings to send out, the PRC 227 heads would be a good option depending on your budget.

 

I was looking at prc heads just wondering about cam matchup in the car.....the guy said it was a comp cam .562 thumper.....I couldn't find a thumpr cam that matched up????

 

I would look at the MMS 223 Sportsman heads and a cam speced by
Kip @ Cam Motion.

 

Without knowing what cam you currently have, it's hard to pick cylinder heads. If this is going to be an NA setup, you'll want to bump compression, which you can't really do safely without knowing what size cam you're currently running.

As far as heads go, it really depends on your budget. You can get a set of 243's/799's ported by companies like Advanced Induction, TEA, Livernois, Texas Speed, etc. If you're in the market for aftermarket castings, take a look at Trick Flow, AFR, MAST, MMS, etc. You could also browse the classified section on here. Oftentimes people are selling used aftermarket castings for a fraction of the cost new heads run.

 

Generally, I would say this is the wrong order - although those are both good cams with a good track record. Generally, I would say pick out your heads first, and then find a cam that compliments the heads.

Also, I'd generally say that if you are comparing two heads and one has slightly more top end flow, but worse velocity, and the other has slightly worse flow, but better velocity, go with the velocity over the peak flow number. This has the effect of "taming" aggressive cams and really not sacrificing much up top.

The metric I favor is the port efficiency, which is CFM flow at 0.600 valve lift divided by the port runner volume. And you need to make sure they are tested on your bore - or at least on an identical bore plate (big bore plate easy way to cheat the number).

--So, lets say you have a head that flows 320 @ .600" lift on a 220cc runner. Thats 320/220 = 1.45 port efficiency

--Similar head flows 330 @ 0.600" lift on a 235 runner. That's 1.40 port efficiency.

--Third option, a head flows 300 @ 0.600" lift on a 215 runner. That's 1.39 port efficiency.

--So, given the above heads, the 220cc runner will deliver the best torque AND will carry power very well up high.

And don't ignore exhaust flow either, but this is where cam selection comes in. In general, I see the best performing engines on stock type heads with 8-12 degrees of split, but the aftermarket castings, I tend to see 4-8 degrees of split. This is an example of why to choose heads first and then cam accordingly - to compliment the heads virtues and make up for the heads weaknesses.

 

What are you're thoughts on the pic as cast 225cc heads vs 2.5 ls6 heads slightly cheaper and slightly less flow. End result is like good useable power across board and if possible hit 430ish at the wheels

 

either head will get you there, honestly. I tend to prefer aftermarket castings, so I would do the PRC between those two. But, at that price for just a tiny smidge more, I'd opt for the trick flow castings. TFS 220 heads are very nice pieces.

 

So with the trick flows what cam would u recommend

 

If you want an off the shelf grind, here's a few:

Cam motion Titan 5
Tick SNS 2
Flowtech Streetsweeper HT

Really, anything in the 227-230 intake range and 234-238 exhaust range with 111 to 113 LSA is going to perform fairly similarly. I'd personally call cam motion up, because they could get you whatever you want.

Sort of spitballing here, but if you ran a 229/235-113+2 and milled your heads to 59-60cc, you'd have very good mid range torque and throttle response, carry power nicely up high, and with only 6 degrees overlap, not really have to fight the cam that much. If you wanted something smoother idle and easier to drive, something like 227/233-114+2 would be tamer and still rev nicely.

 

Now would those choices work for the pecs and what ballpark are we looking at hp/torque wise car is a toy so daily drive ability is not a concern however I wanna be able to drive it on the street and still whip *** so to speak

 

With TFS 220's Fast as Cast heads touched up by Brian, I would go with the BTR stage 2 cam 227/234 113+2 614/576 and BTR platinum dual springs.

 

These are based on the trick flow 220 castings IIRC and are an even better idea.

 

So the mamo heads are around 2100? Prc 1700 so how much is left on the table for four hundred less

 

I've never seen them done back to back on the same motor. The problem is that it's less about "how much power these heads make", because that is heavily influenced by cam selection. The dirty little secret is in a heads/cam upgrade, the cam is more of the direct benefit than the heads. Its just with the trick flows, you'd need less cam to make the same power, so at the same power it'll drive a lot better, which in terms of fun factor AND gas mileage will more than pay you back for the $400. if you really want say same cam and everything - ONLY change is the heads - maybe in to 10-20 range?

look at threads where guys have moved to smaller cams cause the car was a pain in the *** to drive. Good heads and moderate cams are where it's at.

I wish there was somewhere you could go to drive a 23x/23x cam on a ported LS6 head vs a 22x/23x cam on an Uber head and feel the difference. then, later on, if you decide you are willing to sacrifice driveability for power, you only need a 23x cam vs a 24x cam to get really good power.

I know a guy who made 460 (IIRC) on a 239/251-107 cam and stock-ish LS6 heads. He needed 4.56 gears, and ran out of gear at the track - almost couldn't shift fast enough, etc, and now has a stock LS3 and REFUSES to cam that motor, because "I don't want to make it a piece of ****"

 

So with the mamo heads I could get away with say a 228 cam and reach my goal

 

And sorry to keep bugging u but is the 430 gear a hindrance to a build with with mms heads and smaller cam

 

I suspect your cam is a ***** Thumper, given that your car made 398 whp.

227/241 at .050, I wouldn't say that is a hopeless cam but you could do better. Basically, more lift and the same or more intake duration and less exhaust duration. Make more power and less sound effects. A Tick SNS2 227/235 or LPE GT12 227/235 or the BTR 227/234 will all likely make more power and drive better and be easier to tune - thats my guess.

***** Thumpr Hydraulic Roller Camshaft GM LS Seires Lift: .563"/.546"1


http://www.jegs.com/i/COMP-Cams/249/54-601-11/10002/-1

COMP Cams 54-601-11 Details

GM LS Series Gen III/IV Three-Bolt 8 Cyl. 1997-Present

***** Thumpr

1997-Current Three-Bolt 4.8/5.3/5.7/6.0L LS1/Gen III/IV
Valve Setting: Intake - Hyd, Exhaust - Hyd
RPM Operating Range: 2300 to 6600
Cam Grind Number: 283THR7
Duration Advertised: Intake - 283, Exhaust - 303
Duration @ .050'': Intake - 227, Exhaust - 241
Valve Lift: Intake - .563, Exhaust - .546
Lobe Sep. Angle: 109°
Specifications: