v-6 and wheel spacer ?

hi all im thinking of puting a set of 1.5 inch spacers onthe old jeep whats the deal with them are they good bad or what. just want some opions.also,think i found a fuel injected 4.3 in a van. can i use it with the same 350 bellhouseing i got now? how bout my flywheel i just got a new ceterforce clutch in there? my main concern is wireing i dont wanna drop the dough [ok the wife wont let me] for a new painless harnes there is surly somebody that has use the stocker any help will be apprecated thanks,jared