>I hope this qualifies for this section ... I have the AFR 195cc heads (#1031) that came with the 2.02 in /1.60 ex valves on my 94 Z28 that has a LT1 396 with a Vortech T-trim (no inter-cooler ... yet) , and N2O .

my question is should I get the heads ported bigger (8.5:1CR with 64cc now) and go with bigger valves or are these valves adequate for the size of my application ?

 

for a 396 cid SBC size engine i've used 2.080 to 2.125 OD intake valves

the 2.020/1.600 combo will work OK for a mild 396 cid SBC
but 2.055 or 2.080 will definetly make more HP if ported correctly

GM used 2.072" int valves in plain 396 BBC engines in 60's and 70's
and 2.190 OD on HiPerf 396 / 375 HP

GM LS-1 & LS-6 heads along with AFR LSx Cylinder heads respond very well
to 2.055/1.600 or 2.080/1.600 combo even on 346 cid