Does the merc u-joint PN# 75832T crossover to any aftermarket joints, napa, car quest, checker, ect.???

probably, But your asking for trouble.

On the brands mentioned, you'd likely get some Chinese piece. If you took it to a powertrain distributor and matched it up with something like a Spicer piece, you'd have OEM quality- without the anal discomfort of a visit to the Mercruiser parts counter.

On the other hand, how much f-ing around can a guy do to save himself $20?

price was not the motive, I needed a set pronto and could not wait to order, merc, omc,volvo,imco,konrad, don't make there u-joints, one call to rockwell and got the number, picked up a set at local parts store, with rockwell's # on the joint. there was no difference from the one's I removed.

Glad you found what you needed.

That was really a different question. Merc used the rockwell cross bearing for years.

I agree with Chris they cross referenced duplicates are not worthy in a boat.