My old Chevelle, 3350lbs with a 406 running 12's ran faster with a glide, footbrake or transbrake. 4800 should be enough stall for a 406 running in the 11's

a 400 has a 2.48 first,the 350 has a 2.52 stock

turbo
 

i run a t 350 with a trans brake 3640lbs 540 13460ft on the back wheels great trans rossler trans out of ohio

trans
 

Bill i have same set up as you I ran 11.70 i switched to 456 gear just waiting for next year to see what it does. I have TCI trans and i think im putting a brake in to.oh also the 11.70 was with my 373 gear.