I don't see why you wouldn't be able to run 12s with that... but you've got to get your driveshaft fixed first.
My 360 with a 513/533 Lunati cam, X heads, dual plane intake, crappy headers, Holley 750, PTC 9.5 converter, 727, 3.91 gears in an 8-1/4 has gone a bet of 12.21 @ 112 without the...