I bought mine from brothers trucks but it looks like it's probably the exact same one American Classic Trucks has just sold by a different vendor. I bought the kit, engine and tranny, in 2010 on a sale price of $112.49, $24.50 for shipping:
http://www.brotherstrucks.com/prodinfo.asp?number=CETCS59 I haven't installed the kit yet so I can't actually attest to how good it is but it looks like it's well built. The picture shows it sold already welded piece but it comes in 3 pieces so you can shorten it to fit inside your frame rail, boxed or non boxed.
