WAG?

I had a rebuilt, mostly stock, 1960 Long Ram engine. Stock stroke, bored to 426 cubes, forged 9.6:1 lightweight Diamond pistons, stock rods, stock heads with bigger valves and a mild pocket port cleanup (these heads were quite restrictive, I'd guess at only around 220-230 on the intake side) stock 2903 afb carbs (they flow in the 400-450 cfm range) a hydraulic Comp XFI roller cam, lobes have between 236 duration @.050 up to 242 @ .050 with .630 lift at the retainers with 1.5 ratio rockers or .672 with 1.6 rockers, lobe center is 111. with this cam the party is over under 5,500 rpm. We dyno'd the engine and it made 512TQ/405HP with stock exhaust manifolds. Peak torque was around 3600RPM, peak HP was a around 5,000rpm, timing set at 34 timing/74 secondary.

With that in hand;

Your combo would likely yield similar numbers but with the 4.15 crank you'd likely hit your peak torque at a lower rpm and probably 25-50HP due to the better heads. I'd guess with the blow through turbos you'll be gaining between 150-200HP. I'd recommend having your pistons and other combustion chamber parts high temp coated and a water or methanol injection setup to keep things cool in there.