I just got a set of AS 5.3's with I think 11-1 CR. Jay, as it was my understanding, said to use CC 7.350 PR although some people have gotten by OK with the OEM length of 7.4" At 11-1 I don't think that the heads are milled, so what is the reason for the shorter push rod? Smaller base circle on the new cam? Also if some people are continuing to use the 7.4's are they having to do a bunch of shim work? Help.

 

11:1 CR, they are milled.
Anything over .02 mill will require shorter p-rod.
To be absolutely on the money, 7.35 + adjustable rockers.

 

If those heads are milled you will get no compression with the stock length pushrods. We did a car and were not told the heads were milled and installed the stock length and it ofcourse would not start. We slapped the 7.35's in order to get compression. It was kindof a pain as far as time goes but an easy swap. This was with stock rockers.