Make one bro! 2 1/4" steel flanges:bolt em up, make a cardboard base and then cut out of 1/8 plate and tack it up while mounted so as to get the angle correct. 8 stubs of 1.5" EMT formed in a vice to fit the square ports and then weld it all up to a piece of 4" box plenum. Mount a remote filler neck and rad hose spud. Your not gonna find one cheap. If you want to get a SB Chevy TR and get a machine shop to mill you some adapter wedges, they fit with minimal port mismatch.