Anybody running GMPP RRs? Using stock valvesprings? I was browsing throught GMPP RR selection @ gmgoodwrench.com. What is the size of the rocker stud on the LT1? Also... are people switching out their pushrods when they replace the rocker arms? Sorry for so many questions.. but thanks for any feedback.

 

You can re use the pushrods. Probably a good idea to get some LT4 valvesprings, the stockers could float, especially if they have some miles on them. The rockers that come in the HOTcam kit are the ones you want.

John

 

The LT1 studs are 3/8". As stated you can use the stock pushrods if they're not bent, but its better to change the springs.
The pn you need is 12370839.

 

I would suggest getting the new springs as well. The main reason I got the rockers was my valves were floating because of worn springs.

 

-Yes
-Yes, but should upgrade.. if stock cam go with LT4 springs
-3/8" is the stock stud size, however people (including myself) go up to the 7/16 for strength, insurance, etc.
-Switch out pushrods.. It's 30 bucks, and worth the peace of mind....

FYI, I wouldn't go with LT4 rockers, because if you plan in the future puttting a big cam in it, you could run into a couple problems with the way the slot for the lock nut is. Go with the Crane Golds, which in basic design are ALMOST identical to the GMPP, however feature a bigger slot for later on. IMHO I would go with the Comp Pro Mags, I just switched out from Harlan Sharp 1.6 NSA, to Comp Pro Mags, and the difference is night and day, the Comp Pro Mags just are a much much more solid piece.

 

One last question in regards to the Comp Pro Mags. Can you use stock valve covers?

 

My Harlan Sharps cleared the stock ones just fine, and they were bigger than the Comp Pro Mags, I imagine they should, but I went with a taller valve cover just to be safe.