I would have it ground for the following combination:

68 Dart GTS, 3550 w/ driver
511" 4.250x4.375"
440 source OOTB heads
1.875x3" HEADERS
Holley SD single plane
4150/1050ish Thumper carb
A little bit of nitrous (<200 shot)

That would be my suggestion. You have my shipping address : )