carb size for 512 stroker?

FYI The roller cam with hydraulic lifters to 6300 rpm on 6/16/2014.

RPM...........TQ/HP

3000.........519/297
3200.........531/324
3400.........581/376
3600.........591/405
3800.........591/428
4000.........598/455
4200.........594/475
4400.........597/500
4600.........611/535
4800.........618/565
5000.........612/583
5200.........609/603
5400.........594/610
5600.........581/619
5800.........564/623
5900.........557/626
6000.........553/632
6100.........541/628
6200.........531/627
6300.........518/622

Too busy, never did get to the 950 carb.

Installed the 2" spacer underneath the 750 cfm carb. Still using the solid roller lifters.

RPM............TQ/HP..........Back up pull

3000..........509/291...........513/293
3200..........536/326...........534/325
3400..........586/379...........585/379
3600..........595/408...........597/409
3800..........597/432...........599/433
4000..........607/462...........609/464
4200..........610/487...........608/486
4400..........611/512...........610/511
4600..........613/537...........613/537
4800..........621/568...........619/565
4900..........626/584...........622/580
5000..........621/591...........621/591
5200..........619/613...........617/611
5400..........613/630...........613/630
5500..........605/634...........602/630
5600..........601/641...........595/636
5700..........594/644...........592/643
5800..........585/646...........578/638
5900..........577/648...........573/643
6000..........570/651...........572/654
6100..........562/652...........566/657

Now, I don't know what you are looking for performance wise James, but the first dyno run in this post is what you might expect with your present cam and carburetor, if you have your heads ported.