B1's flow about 5 percent more ?, and have bigger runner volume. I forget how much, but the Mcfarland formula puts them over 500 rpm higher for peak torque over a good set of 440-1 heads, depending on short block size.

Last edited by gregsdart; 12/13/15 11:40 AM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky