Ok hears the deal, I have an 07 gmc Sierra classic with a 5.3 with stock 862 heads. My question is what kind of power gains will I get from the following. If this matters it's a crew cab short bed.

210/218 .551 .551 112 cam
Pacesetter longtube header
Ls6 valve spring
3200 circle-d converter
3.73 stock gears and
I'm thinking about swapping out my stock 862 heads for 243 with little head work to them.

 

I'm not good at guessing hp/tq numbers, but I can tell you that it will be a nice combo for sure. I'd up the gears a tad bit more to 4.10's though myself (what size tires are you running?). tdrumm used to run that cam in his 2wd rcsb, and it was excellent, even with stock heads, converter, and gears. Each time he modded it more, it responded even better. By the time he was done, the truck had WCCH StageI 5.3 heads, 4.10 gears, a FLT Level5 60E, and a Yank TT3000, and I felt that it was a perfect match. I remember Tom getting used to the converter real fast and wishing that he had went with a 3200

 

isnt the 07 5.3 have dished pistons? i believe so, if it does and you put 243s on it youd end up killing your compression ( wouldnt you ) id go with a set of 2.5 prc heads

 

See that's the thing I'm not sure what pistons I currently have. Anyone care to chime in? But I hav thought about upping the gears to the 4.10s, what kind of diff. Would it make?

 

O I forgot to mention I will also upgrade to a pblvl2 trans. In case I decided to go larger motor

 

you have dish pistons, you will need to mill them atleast 35 to make a compression difference. if you are looking to go with a set of heads just send yours to Texas Speed and have them turned into a PRC 2.5 and deck them imho

 

thx. niff if i can find another set of stock heads ill do that so i can still drive my truck.since its the dd

 

stop being scared and put it together!
If not i have someone who will buy that cam

 

You'll need a 2 piece driveshaft soon.. <221/226>

 

u still have it?