flippincamaro

iTrader: (23)

I have searched for this and havnt found it yet but what is the stock valve size for the 5.3 if it is the same as the 5.7 head why does everyone say not to put a stock 5.3 head on a ls1 that it will hurt you and not gain is this true? Main thing i want to know though is the valve size and how much i can shave off them without changing out my new pushrods which are 7.4 comp cams with a cam that is .591 .568 lift thanks for any help about how much compression will i be at? lots a ?s thanks

PREDATOR-Z

It has to do with flow#'s of stock pieces.
Ported 4.8/5.3 are some of the best power makers with matching cams.
Stock valves are the same size.61cc chambers.
Most applications switch to 2.02/1.57 (Stage 1.5/2)

66deuce

iTrader: (1)

stock 5.3 intake valve size is 1.89in.exhaust is 1.55,the same as a 5.7.