I never had them build an engine.
Are you going to use B1 Mopar heads? That is what they are known for.
I bought a set of "new" B1 original heads from another racer that went in another direction before he built a complete motor. That racer had them ported and prepped, but never used.
I have talked to Scott Koffel a few times, and he has been helpful.

B1_Heads_Decal_5inchBlack2_crop20.jpg

1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1