i dont understand the question, but if said motor is setup well already then why not keep motor the same..
for sake of discussion
what is price of building a 115 rod stock crank? my understanding is, that it runs around $450?
for about that price you can true and weld a stock crank and port your cylinders and be ahead of the game.
im also thinking that if someone wants to put $450 into a crank then why wouldnt they be porting the cylinders and modifying the head anyways. if so, they would be once again ahead by going ahead with the 4 mil. even if you do run the spacer place temporarally, the next step would net more overall power (porting and 4mil domes)