Hey guys I just picked up a set of PRC Stg 2.5 5.3 heads from a friend which were milled to 59cc.



Will I have any problems adding these heads with my current hardened pushrod length of 7.425? At the time I got these I was cam only on stock 241's Comp recommended 7.425 to quiet down valvetrain a bit. I am also getting some hardened 7.4 rods with the heads so I can swap if needed.



Also what size head gasket should I run? Im looking for over 11:1 compression but dont wanna have ptv issues. My friend had a torquer v2 cam with these heads and ran stock thickness. My cam is slightly smaller.



His cam -Texas Speed Torquer 2 232/234 .595/.598 112+2

My cam- Comp custom grind 228/230 .588/.592 112+2

 

1- you'll need to measure for pushrod length, chances are you'll need shorter than 7.400 with 59cc, get a pushrod length checker gauge.
2- Stock gasket, you'll be around 11.4 SCR

 

Thanks PREDATOR-Z I had a feeling you would respond

Would GM MLS gasket stock thickness work good? Ill measure and also check with TSP on the push rods because he ran the 7.400 length with his cam(tv2)and these PRC 5.3 59cc heads. He had bought the cam, heads, pushrods etc recommened from Texas-Speed as package and was running a stock gasket size as well on his 04 GTO.

So the heads + cam were essentially set up for the the Torque v2 cam just seeing what differences come into play with me having a slightly smaller cam in my 04 GTO.

If it really came down to it my dad bought his cam so i could swap mine out and add his if need be and my dad would take mine but I love my cam and really dont wanna take it out again lol

 

The question is "what was the preload on your buddy's setup?"
Shops have a nagging habit to recommend 7.400 for about everything assuming the hydraulics will make up the rest. But that never solves the issue of proper preload, which is directly related to pushrod length on our non adjustable rocker setups.

So, proper way is measure.

Yes GM MLS is perfect.

 

Ok thanks!

 

He is right !!!

 

Like Predator said, you really need to measure this one! There are too many variables in your combo to guess at this.

The $20 tool would be well worth the investment!

 

Assuming stock bottom I think your PTV will be very close milled to 59cc even with a GM MLS HG

 

The previous set-up was tqv2 cam with stock gasket and 59cc heads was on a stock bottom end and had decent ptv clearance but im unsure the exact amount he had? i'll ask him im new with ptv stuff btw

would I have less ptv clearance than he did with a slightly smaller cam asuming all other things in set-up were equal? I would asume more ptv clearance but I will get with my friend who knows a lot more than I do and measure things out.