I can give you some real track fwhp figures from the days I ran my all steel s/strip '71340 Cuda at SP and I think your all a bit optimistic on 340 hp numbers. 3500lbs+ w/me
spec1. stock 340, small hdrs., dual plane, 750DP, .484/284 hydro, 727 3500stall/3.55's, 8x26" slicks> 13.30@101 = 301fwhp good tune.
spec2. Added race hdrs., Holley Strip dom intake, 850DP, .590/312 solid ft, 4200stall/4.30's, 10x28's> 12.39@108 = 367fwhp good tune
my 2cs