EXPANDING DOGHOUSE (CHEVY FOR FORD)

If you are putting it in a pickup it won't fit without major modification. It's too long. Best way on a pickup is to use the original Ford box and weld the flared sides from the Chevy box to it. You only need to widen it from the radiator support back so you'll have to cut and shorten the Chevy sides. The inner seat support will still work but you will have to switch them from side to side to get the correct offset. Also the flared sides on a Chevy box are about 1" taller than the fenderewerll on the Econoline so if you bolt the seat to the Chevy box side it will be to high. Here's a photo of a set of Fiero seats installed in my old 65 pickup. I used the original Ford box and welded the Chevy sides to it. I cut the sides down 1" in height and only shortened them 1". After I had it all welded I felt that it would be a much cleaner look if the sides only came to the radiatior support.
Fred

V8 VAN CONVERSION COOLING TIPS

Photo is a reference shot only. 

Once in a while I come across a person who is so intelligent and informed in their opinions, I don't dare attempt to paraphrase. With that in mind, here is an excellent series of tips taken from E66PU on the vintage-vans.com site: V8 conversion cooling tips