Bellhousing Compatability

Hmm, so I guess what I should ask now is (now that it appears that I have to buy ANOTHER one) how do I know that I am purchasing a bellhousing that will fit?

I was pretty much just going off of this when getting my bellhousing...

Reconditioned original 10.5" small block bellhousing cast #3743859 to fit 1975-6 A-body/1975-80 F-body/1976-80 truck (can also be used in B/E applications with appropriate fork pivot bracket)318/360 A-833 overdrive applications, 5.125" bearing retainer opening, uses 130 tooth flywheel.