Not sure why anyone would not use a 390 if its an original 390 car. Scat makes some awesome stroker cranks that are a drop in deal,do some head work decent carb easy 450 hp I race a 67 mustang in c/sa 3090 lbs 10.84 by best et... thats a stocker... give me a stroker crank bigger cam...... you get the pic ....LOL
Umm..my 390 car hasnt been a street car in a long time although i own a 1968 car with a 428 that is around that 450 number i put maybe 6-8 thousand a year on gets around 14 mpg but.....370 gear loose convertor, big carb wasnt concernd with mileage.:nogrinner as far as a crawler motor i think the fe is just tooooo heavy even with aluminum heads really any big block i think ( just my opinion )
Ah, I see that is interesting. Reason I ask is because the ZL1 427 engine was completely aluminum, and allegedly produced over 500 hp--now at what cost to MPG I'm not sure, but I guess it was the actual engine architecture that did it.