rabinaba

I’m swapping an LS1 and T56 from a 2004 Pontiac GTO into my 1981 Corvette. I’d ideally like to be around 400 hp at the crank (+50 hp over stock engine) and I’m thinking a cam is probably the way to get there (in addition to long tube headers, CAI, better cooling, etc.).

I very much dislike the sound of a choppy engine. I like a deep throaty exhaust note, but excessive chop just sounds like the engine is going to give out. So I’m thinking about doing a mild cam, but the numbers make very little sense to me. So what would you all recommend as a mild cam to get 40-50 more hp, keep the chop to a minimum, keep the car reliable (I need it to always start), and keep the engine from blowing up (it already has 150k miles on it).

Also, what else would I need to change if doing this? I know I’ll have to get new valve springs since mine are likely worn out by now. Do I NEED to do pushrods? Injectors? If I don’t replace the oil pump is the engine going to explode??

01CamaroSSTx

iTrader: (3)

If you have good oil pressure then I wouldn't be too concerned about the oil pump causing engine failure. Do you have any idea of the condition of this LS1 engine? What do the bores look like and are you seeing good compression? Perhaps do a cam with duration in the 220's and lift in the .590's and run a single spring. Very unlikely you'll need to change pushrod length when swapping the cam but a new set of stock length 5/16 chrome moly pushrods wouldn't be a bad idea. Check your P-V in order to find out how much you can mill the heads in order to gain some more compression or better yet find some 243/799 heads to replace the 241's. Look at improving the exhaust system and getting a new tune.

G Atsma

A cam in the 220 duration range WILL lope but not "chop".
Get something like a 212/218 .550/.550 114LSA and you will gain 50+/- HP easily with minimal lope.

wannafbody

iTrader: (2)

Cam Motion Titan 4, Summit stage 2 or TSP 228/232 will give good midrange and top end power.

Summitracing

Check out the Summit SUM-8715R1 Ghost cam. It's called that because it's very mild in it's behavior but makes power rivaling cams much larger in size. Valve springs are a must...stock springs weren't good new and are terrible by the time they get that many miles on them. The SUM-174004 beehives are very reliable, light and easy on the valvetrain. .080 wall 7.400 pushrods are a good idea to keep the valvetrain stable with your newfound rpm. Many other parts of the engine are pretty good as is. You could freshen the LS2 chain inexpensively. Depending on how many miles you have on them, your lifters may be fine too. Your injectors are probably going to be ok BUT we recommend running it on a chassis dyno with Wideband o2 to verify those nor the pump are weak.

Tuskyz28

rabinaba

Ooh just saw a YouTube video of a CTS cold start with this. It definitely has the least lope out of any cam I’ve heard so far.

Tuskyz28

Cam pushed out 408 rwhp with no port work done to the heads.

GMRL

Scoggin Dickey LS6 Power Max cam seems to be a good candidate based on your criteria

MuhThugga

That Hawk's cam is intriguing, though it looks like it loses a bit below 4k.

rabinaba

Oh interesting. I don’t want that, I’ll rarely push it to 6k.

99Silver6.0

iTrader: (2)

I used the WS6Store (TSP ground) high-lift hot cam. Its a 218/227 .600/.600 112+2 (-1.5 overlap). Not big by any stretch of the imagination but has a nice slow rolling lope and its very tolerant of lower idle speeds. Im idling it at 650.

Abs

To be honest, you will get 400 crank hp with just the mods you listed and a good tune. No cam necessary. I have had a 2004 gto since new and it's really only lacking above 5k where the torque starts to drop. Below that is fine, and since you rarely go to 6k anyway, you honestly don't need to swap cams to hit 400 crank. Also I saw your other thread in april and you referenced having an ls1 intake. Lucky for you, the 04 GTO has an ls6 intake from the factory. All the more reason that you would hit 400 crank.

If you are set on a cam though, you might hit 400 wheel hp. The summit 8715 ghost cam was mentioned, but that performs the best at the top of the rev range where you won't be. I'd suggest the summit 8720 at 218/227, .600, .600, 112+2 or the aforementioned WS6 store high lift hot cam with the same specs. The WS6store cam has lobes that are a little less aggressive (more advertised duration), but the summit cam would give a little more power. Depends on if power or valvetrain friendliness are more important to you.

Utinator

It's going to be difficult to swap cams without going way over 400hp crank. As Abs mentioned, you will probably make 400hp at the crank without a cam, but a cam is always a nice upgrade.

The Summit "ghost cam" will not be choppy at all, but will put you way over 400 crank hp. As mentioned previously, That cam does better in the higher rpm range. All the stage-2 "truck cams" (212/218) are going to chop a little. For what you are wanting, I would recommend the BTR Torque cam. It's a single pattern cam just barely bigger than the stock cams. It provides more power at every rpm over the stock cams, and will easily make 400 hp at the crank. You won't need bigger injectors, but you will need better springs. I would get the Summit LS6-spec springs (don't know part#). You never really know if you need new push rods until you measure, but it's usually not needed with that cam. The Summit LS7-spec lifters are a good choice at this time too.

Tranz Zam

I run the TrickFlow 228/230 .585 112lsa in my 78 Vette with a 6.0 and a TH400. Made 372rwhp with mid length headers, 102mm throttle body, with stock injectors and no head work.

Pulls hard.

68Formula

If you want something that doesn't chop, easy to tune, and you're not pushing it much past 6k consider the Summit SUM-8719R1. Easy 400hp crank hp on a 5.7L. And you can use LS3 factory or similar aftermarket springs.

Markolc81

iTrader: (1)

https://sdparts.com/i-24138755-sdpc-...Power+max+plus

That will idle closer to stock, and have the power you want. You can also use all your stock valvetrain, just need better springs. They also have a slightly milder cam called the LS6 Power Max (no plus) if you really want a stock idle.

Price is right for both cams, even with the need for better springs.

With headers and one of those two cams listed above, yeah you'll be over 400 flywheel.

Lots of great suggestions with the posts above also.
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