MoMoney789

I recently bought a 99 c5 convertible automatic with 51k on it its currently completely stock. I already ordered and axle back and a x pipe and I'm wanting to get into the motor soon. I've heard of people replacing the heads, cam, and intake with ls6 parts and I'm wanting to go that route because it seems to be less expensive and still have good quality parts. I'm not making this into a strip car just a weekend warrior. What's your opinion on how well this setup will work? Thanks in advance

CamminC5

It'll work, but you can pick up aftermarket parts and get more bang for your buck. There are plenty of mild aftermarket setups out there that will keep the car drive able and net you more power than going with all LS6 parts.

Pounder

LS 6 intake,Vararam CAI,headers,a tune,for advice call ether one of these guys.

http://www.eastcoastsupercharging.com/

http://www.corvettes-of-westchester.com/

neutron82

what are your power goals?... you could easily make over 400rwhp on ls6 heads and intake so those aren't bad things to do but if you go as far as the cam I would go with an aftermarket unit personally

enoniam

Building upon CamminC5's comment, my car's running ported LS6 heads with aftermarket cam and intake manifold. In particular I'd look at a cam bigger than the LS6's.

MoMoney789

How do you like the ls6 heads? Do you think they were worth it?

enoniam

I'm probably not the best to ask as I bought the car with those heads already on it. Suffice it to say that with those heads, a Weiand/Lingenfelter intake manifold (which many on here will tell you was a decent choice when first came out but not so much today, but still superior to stock LS1 intake), and a Comp cam (XE-R lobes, 220/224 degrees duration at 0.050, 114 LSA, 2 degrees advanced) car put down 383 rwhp on a Mustang dyno two summers ago. Rebuilt the engine last summer with same heads (mildly milled)and intake manifold with a Comp cam with XE lobes at 228/230 duration, 112 LSA and 2 degrees of advance and judging by the increase in airflow as seen by the engine computer via HPTuners scanner interface should be making about 10% more power than before. Given typical auto drivetrain loss on a dyno engine should be making well over 500 crank horsepower.

CamminC5

I run ported Ls6 heads with oversized 2.040" SS Intake and 1.575" SS Exhaust valves, but never had them in a NA setup.

If you can find a set of 243's (LS6) heads (especially ported) at a good price and a LS6 intake manifold. That will be a great improvement over what you have. However, picking a larger cam would be a better choice over going with a LS6. Sure it's a good cam, but there are street friendly aftermarket cams that will get you better gains.

zeevette

For the biggest kick in the butt; gears, and converter, then engine.

S.C. vette

Care to make some recommendations?

CamminC5

Texas Speed 224R or 228R cam.

I had a 228R with headers and full exhaust. Car made 411 through a manual. Street manners were excellent. However, a good tuner is the key dialing it in.

Here's a video incase your curious how it sounds.

enoniam

The Texas Speed 228R looks to be pretty similar to my Comp 54-428-11 that I'm very happy with. The 228R has higher lift but 2 less degrees of exhaust duration. I'm running stock rockers and wouldn't want to go to 0.600 lift with them. I also would lean towards having more exhaust than intake duration, particularly if running stock heads and exhaust. If running a very free exhaust with long tube headers and ported or aftermarket heads having the exhaust and intake durations the same may make the most power relative to the other tradeoffs in cam selection but in most cases having more exhaust duration is desirable.

Here's the cheapest place I found online to buy Comp cams. Delivery was prompt, unlike an experience I had many years ago with Thunder Racing. I ended up cancelling the Thunder Racing order after waiting a month and went through Texas Speed for that cam and they also were very prompt with delivery.

http://www.ws6project.com/user_stor/...roducts_id=161

Edit - by the way the above link notes that this cam' operating range is 2000-6800 however Comp's web site (as well as Summit's) indicate 2200-7200. I've got the computer tuned to shift at 6800 but have seen a bit over 7000 in my data logs on the 1-2 shift and therefore have the rpm limiter at 7050. Engine is still pulling hard at shift but I don't want to take the LS2 stock rod bolts that I'm running any higher. Note that this Comp calls for pairing this cam with an aftermarket intake manifold. You will also need bigger injectors to feed the engine and with that undoubtedly will need a custom computer tune.

enoniam

And building off of zeevette's comment, with cams as big as what CamminC5 and I are running a higher stall torque converter is generally recommended. Gears can be a matter of choice - I'm running the optional 3.14 gears that came from the factory in my car.