B body 8.25 in an a body. Help

So I kinda just wanna double check. If I got a b body 8.25, do I need to relocate spring perches and shorten the housing and axles to fit my 70 dart? I figure since u have to for an 8.75 b body ud have to for an 8.25

Side note: the reason I ask is I will attempt to purchase a b body 8.25 rear (duh). I don't suppose there is anyone in here that is local to me and willing to do a fabo young gun like me a favor?

I dnt have the equipment, skills or know how to do the required mods to make it fit in my dart. Anyone wanna maybe do that stuff for me (if I get the rear, of course)

Thanks for any info