Don't do a burnout with the street tires. Quick chirp if you want, but drive around the water.

My very similar combo ran a best of 7.43 in the 8th (so about 11.70) with 28" slicks on a 3.91 gear.

10.2 compression 448 stroker
Magnum 282 Solid with 1.6 rocker so .528 lift 236 at 50
1.75 header 11 inch TQ
Performer RPM

A smooth accel. foot, I think, will get you a 12.10 or better is my guess.

The old mild 383 would get 8.43 on street tires, so you got that beat.