I'd like to get a 12-bolt rear to put in my garage and start slowly building up, as time & money permit. I understand the ones from 3/4-ton vans were the best because of the extra 4" of track width. Rather than going to the yards and asking for a "12-bolt", which will probably get me a bigger pricetag, I want to ask for a readend for a "(whatever year) Chevy V20, C20, whatever, van". What are the years and models that I should be asking for? Thanks Semper Maintenance!