It's a built Glide and Ford 9 rear. 3:89 gears. The motor is 454 .030 over. I have a comp flat tappet hydraulic cam and 396 iron heads. 850 Holley. MSD mech dist and 6AL box. I really didn't do an all out pass. I think it would get into the low 13's easy enough with the current setup. With aluminum heads and a solid roller, I bet it would do much better! But, for now, we are going to run it as is and have some bracket fun.