400 low buck dont give a

to the OP- spend all your motor mod money on a CSU or Pro Systems blow- thru carb and a T70 turbo- fab up hot and cold side piping and boost it - then it will be a blast...

if you just want a fun drivable car - get a OEM new replacement 68 440 or 426 Hemi hyd cam from Napa, some nice Comp valve springs, Ede dual plane intake, and with the 906's milled that you have should be enough to have fun

I also agree ditch the 4.56's for 3.23/3.55's