318 crank pulley correct size??

So I'm looking to replace the crank pulley on my 1975 318 block with pwr steering and no A/C.
Its a two groove, 7 7/8" OD, by 4" OD on block side and about 3 3/4" deep.
This motor is in a 67 b-body, but you guys no alot more about small blocks than bbodiesonly.
(don't tell'em I said that)
Anyway, finding specs on the correct pulley size has been difficult.
I don't know where this pulley came from.
The closest I've found is 7 3/8" at Crankshaft Pulley with Power Steering w/o AC
Anyone know exactly what I need?
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