Daryl T

I'm planning a build up for my 2005 crew cab with a 5.3L. I want to use GM performance parts CNC ported LS6 heads PN 88958622 and LS1 5.7 camshaft PN 12560965. My question is because the new heads have a 62cc chamber heads and the stock heads are 61cc, will there be a compression problem due to this, or because of the cam, will it make up for any loss?

Thanks for any advise.

ltr450ryder

iTrader: (13)

U will loss a little bit in cr and I would bother running ls1 cam I go with a 212/218 low lift

Whitecrewcab

iTrader: (2)

Why put a low lift version in when the heads are c&c'd?? If you are gonna cam it, take advantage of the port work. Something like a 212/218 high lift or maybe even the LSR 215/223 with .604/.610. Go ahead and mill the heads .030 and run a .040 head gasket and gain a little compression.

Daryl T

So the heads are a good choice, just go to a higher lift cam and I should be alright. With already 295hp, I'm trying to go in the neighborhood of around 350-400 and keep it streetable. Will this combo work for what I'm looking for?

ltr450ryder

iTrader: (13)

With the lsr cam u and heads u should be close or above the 350hp and is Ur cc 4wd or 2wd?

Whitecrewcab

iTrader: (2)

The heads are a solid choice, I would do what I could to bring the compression up. The runners are a lot bigger than the stock heads and it will be a little soggy down low compared to the stock stuff but above 2500 rpm it will pull a lot better. Raising the compression will make up for that and make even more power upstairs. The heads being ported makes them flow at lifts where the stock heads quit. Use a cam that has somewhere between 212-218 @.050 on the intake side and as much lift as the springs will allow.

454SuperSport

what exactly are you looking for from the setup? willing to run a loose converter? do you tow with it? we can point you in the right direction with alittle more info: D

Daryl T

My crew cab is 2wd and I want to sometime that can play but not afraid to work.

sand man

you allready have the 243s right?

if so i wouldent buy the CNC ones from gm , i would install gears , and LS6 cam with NNBS intake manifold this should come close to the cost of heads and 212/218 cam
and will have better results too and if you mill your heads then thats another gain that costs nothing while the heads are out

Daryl T

If I'm wrong, I have the 706s heads, are these heads ok or should I start looking for apair of 243s. The NNBS intake is new to me, could you please explain, and what site that I could purchase one. For the gears, I'm currently running 3.23s, thinking about going to the 3.42s, but no higher that 3.73s. Thanks