Quote Originally Posted by camaro_fever68
The 421 will make more power and will run faster no doubt especially with the Vic Jr heads.
I thought so too. I had those heads (my son got the hand me downs) before all the port work and I ran 11.78 @ 111 with my ride and a 406 but my truck is 400 lbs lighter.

Quote Originally Posted by camaro_fever68
I see a lot of potential for the current setup though with tuning and traction. Taller tires will hook better due to the sidewalls.
Agreed, next season, bigger tires. He's got the gears and converter to handle it.

Quote Originally Posted by camaro_fever68
.... go with a 412cid. That is a 3.8 stroke crank and 4.155 bore size. The heads you have will fit that combo well.
Why not a 420/421? Too big a stroke?