I am wrapping installing a MS4 and PRC LS6 heads. I got the double roller lined up and installed, i went to rotate the engine over with 2 rockers installed per ls1howto and it is somewhat resistance to rotating. Could this because of the springs which are the new TSP double springs or can I have a possible PTV issue?

thanks

 

are the spark plugs still in, if so you are building compression.

 

 

no spark plugs are in, but i have on the passenger header on. i went with this combo to avoid a PTV issue. Also, per the cam card it has 1 degree of advance grounded in.

 

Does the motor get stuck near TDC of the cyl with PR's? Or does it get stuck at some other point in the stroke? You should be able to tell.

 

This is a judgement call on your part. The springs are going to create some resistance, but not a lot. If it is considerably harder to turn than you think it should be it probably is a problem you should look futher into. This is the time when your arm becomes a torque wrench, but it doesn't give you a specific value in ft/lbs. It either says "Normal" or "Tear it back apart".

 

This may sound like a stupid question, but did you get the 7.35 pushrods instead of the 7.4's? If so, I would double check the alignment of my timing chain, just a little out can be catostrophic, especially with that much lift.

 

is the car in neautral?

 

i got the 7.4's and car is in netural. I took off the intake rocker and left the exhaust rocker on and i am able to turn the motor with little resistance, however when i take off the exhaust and leave the intake rocker on, it has way more resistance. I lined up dot to dot no adv or retrd. If I were pull the head, can I re-use the graphite gasket, its brand new?

 

I need to know the same thing about the gasket

 

yes the gasket and bolts are good untill you start the motor because no real pressure is built up yet. just make sure you untorque the heads the way you torqued them so that they realise evenly. also, are the heads milled at all, because i just got done with some patriot ls6 stage 2 heads on a t-rex cam yesterday at it started up right away with no problems.

 

also as i left my computer i just remembered, did you get the .040 or .052 gaskets. if you got the .040 gaskets then you have ptv issues because that .012 will make a huge difference. let us know man.

 

No, the heads are not milled. They are PRC LS6 with stock valves. I'm not sure if I am overworried, I just dont want to mess anything up.

 

Take the heads off and measure PTV. If you're hitting with an .040 gasket, that .012 (that you would get with an .052 gasket) is not an acceptable tolerance. You should be closer to .080 for PTV clearance. Even though its a PITA to remove the heads again, it's not worth the risk of tearing up your parts.

 

I am using the stock gm gaskets, which I am assuming should be .052. Can I just pull one head, driver side?

 

Pull one head? I would say yes. But Don't you have to retorque the head bolts to get acurate PTV clearance readings? This is why I'm going with head studs next time I do this swap.

 

pull the head and check it with clay on one cylinder

 

so i can reuse my headbolts and felpro gaskets on my 6.0

 

If I'm not mistaken, the PRC heads are milled .05 to ensure straightness. I read this in GMHTP in the article they did on the same setup you have. They said to use a 7.35 inch pushrod to account for the difference in the head, I don't know if this is your problem but it is worth checking. I could be wrong, if you'd like you could double check my info in the tech articles at gmhightechperformance.com. Hope this helps!

 

anyone