A Body swap with E body 8 3/4 with 4link

I realized the OP is talking about a 4 link anyway, so the whole deal with moving the perches is irrelevant.

Also, if you’ve got the skills to install a 4 link then you should be able to shorten that 8 3/4 too. I also wouldn’t worry about making it A-body width. Pick your wheels first and then make it whatever width you need to make them fit.