I need the cylinder head specs for the 5.3's, as I am about ready to do some porting and polishing, and would like to know the suggested specs for these heads, as in should I go with a normal 30-45-60 valve job or is there something else these engines like? Also, any other specs would be appreciated like valve seat angle, backcut angle, min. valve margin, etc... Thanks a bunch.

 

Also, what valve seals do you recommend for the 5.3 heads?

 

I would call pete @ CNC.Better yet I can call him and let you know.

 

You would be a savior if you could do that. Wow, first you sell me the heads, and now your doing this......Thanks..... I owe you one.

 

Any info yet? Or better yet, any # I can call to talk to someone about this? I dont wanna just start calling all of our sponsors or something....

 

these are stock values:

valve face angle: 45 deg
valve seat angle: 46 deg
valve seat runout: .002" max
valve spring pressure opened/closed: 76 lb@ 1.8"/220lb @ 1.32 in

those are about the only values I have that might help. Ive got a full spec sheet on lm7 vin t / l59 vin z engines

 

yeah ive got that, but was wondering what some machine shops might do, like 3 or 5 angle valve job and so on...thanks though...