definately go with a higher stall in a smaller motor, just like sheppard said if you can't fit the rpm air gap try just a rpm

 

what heads are you running
and what is the compression ratio
my 81 z28 with a th350 and a 2400 stall
327 with .240 dome pistons 76cc heads no port job and no polish
with a 218 dur and .454 lift cam 600cfm carb and edellbroch eps intake with long headars ran a constant 14.6 @94mph in a 3800lbs pound car
by the way 342 gears and 9.6 compression and that was the firs time at the track with it had too much wheel spin
new motor 327 with same pistons ex284 cam stock heads with port and polish
that i did myself trac bars and a set of 295 50 15 tire going to the track on the 10th I WILL LET YOU KNOW WHAT MY TIMES ARE
my buddy wants me to run nos but I want a 12s car without it

 

ooooohhh and now im running a 3500 stall

 

of course, you can barley count nitrous.
i want a 12s car to, its just not gonna happen with this setup. needs a couple more cubic dollars