I ordered it from my work, Towers and Harwood Performance, you need the spacer if you want to keep your stock pulley location. It is only 17.95, that plus the balancer (150 somthin) came to 175 even. Also, I am running a stock reman'ed water pump from oreilys.
You can talk to the guy at 1-785-537-4100... he is VERY knowlegable on carbed 302's, builds them all the time, he would know anything, little iffy on the EFI, but if you need parts, I would try him first.