I got me a 4 speed! (and I need some help!)

A few questions.
Is the trans from a car or a truck?
Does it have all of the shifter rods and linkage?
Can you get the original bellhousing and is it for a V8 or a slant 6?
At any rate, it's much easier to machine your bellhousing ( it should have both bolt patterns) to fit the retainer on your o/d trans, and your clutch should be fine if it's in good shape, and for sure your yoke for your drive shaft is different than the 3 speed (same as a 727 auto) and the length is different too.
If it's out of a truck, it's a big bag of snakes to make it fit and work, but it's not out of the question.
If it's out of an a or f body, you're laughing.
I would like to see some measurements.
Short output extension, it's an a or f body, long it's a truck. (It should be roughly the same length as your 3 speed to be an a body one.)
Same transmissions other than that BTW.
Clutch linkage should be the same.
I hope this helps.
Tom.