727 or 904 which way to go

i have a 727 that has been sitting for several yrs obviousily is goin to need rebuilt that a guy wants he is wanting to swap a rebuilt 904 he wants the 727 to put in his derby car which way should i go keep the 727 and rebuild it myself or swap and take the 904 my dart will see mostly street use with the occasional trip down the 1/4 mile.not building a super aggresive motor.