With a roller and decently flowing SR's I would think you could be in the 630 range pretty easy If the heads are only 'touched up" I'd say right at 590-600. But it doesn't really take much to get an SR well over a comparably prepped E-head and 10.88 is decent enough and would work well with that roller, you've got a lot of the right parts there to make over 600. It's a swag without the headflow numbers but I'm thinking if you have a 2.19" intake you could be flowing about 310 at .550 (they'll go about 285 OOTB IIRC). A 252 intake lobe seems small seat to seat but your .200-up durations should be better than a ~265 @.050 solid flat tappet which would certainly support a 600 hp motor like I would build it anyway.

Beautiful car by the way. I know yellow is a tough color to photograph accurately.... I'm sure it's eye-popping in person!!