I measured my crankshaft pulleys for inside diameter (approximate):
5-3/8" diameter on 216 for 5/8" belt
5-1/2" diameter on 235 for 1/2" belt
5-3/4" diameter on 235 for 3/8" belt
That doesn't seem enough difference to be a big problem but I will take your word on it. I ordered an adaptor plate tonight. Later I'll order a 54 water pump and gaskets from one of the catalogs or websites.
I'm excited to be working on my truck again. I've had it four years without much progress.
Thanks
[censored]
1946 Chevy Half Ton ('56 235, '86 T5, '79 Camaro Z28 rear end, working on the '85 Jaguar XJ6 IFS)
1976 Margay Panther X, MC91B