Well obviously you have to check the bores- you might get lucky and find factory hone marks- or you might find gouges and a big ridge
Found some specs on the Stock cam
432 420 lift
289/287 cam lift
284/293 duration SAE .006 AT THE VALVE .004 AT THE CAM (comparable with CRANE)
206/209 duration @.050
113 lca 110 intake centerline 115 ex centerline
IO 22 BTDC IC ABDC 82 EX open 74 BTDC EX Closes 39 ATDC 61 overlap these are SAE or .004
-1 22 40 -11 @.050
now look at the intensity or lack thereof 60 degrees different on the intake close .050 to .004
any other questions on why you have no dynamic compression on top of low mechanical compression?
let's compare with the smallest Lunati Voodoo
454 lift
253/256 @.006 (not .004)
208/213 @.050 (not much different than stock)
112 lca
Intake Closes at 54.5 @.006 (vs
[email protected] for stock) (this is the same intake close point 54 as the 256 comp chevy cam)
you could take the Howard HM2063164A lobe and have it ground on a 110 lca with an exhaust to match your headers or manifolds
.475 lift 252 @.006 206 @.050 126 @200
Both the Howard and Lunati get the intake closed much earlier than stock building dynamic compression
about all you can do without a piston change
with a chvy size lifter you are lucky to get .430 stock lift at these durations
for example the way obsolete Edelbrock performer has
278/288 SAE duration (10 degrees shorter than stock) 204/214 @.050 (bout the same) but only .420/443 lift