For 1500 you could build the HELL out of a sohc and make well over 350 hp. Or you can have a stock ls that could snap a rod anyday at the same power.
Besides that, the d16 with a longer stroke will make more tq down low than the b's for the same hp. If you have them oney go with the ls, but build it as well. If youve only got that extra 1500, use your y8..upgrade the oil pump (or modify it, y8's have oiling issues) and go kick some dohc ass.