My '75 dies when put into drive or reverse. Is this a locked up TQ. If so is this gonna require a trans drop? Just my luck hah.

 

Your car came with a TH350, doesn't have a lockup t.c. It would have a lockup if someone swapped in a 350C, 2004R, or 700R4. You'd know if you had either the 200 or 700, since they're overdrives.
What rpm does your engine idle at? Could be it's set too slow, which can cause the engine to kill once put in gear.

 

My idle is about 900 but I cranked it up when I first started having issues and it would still stall. The TQ is not clutching basically.

 

Your torque converter's stall speed may be too low for the cam you have. If it's the stock converter and if you have a lopey(long duration) cam the lack of torque at idle would cause it to die when put in gear. Also I'd suggest checking your initial ignition timing as that can also affect low rpm torque.

 

When you're shifting from park to reverse or drive, I presume you're stepping on the brake pedal. For fun, try stepping on the brakes without shifting out of park.
Just curious if you may have an electrical short associated with your brake lights that might be somehow killing power to the ignition.

 

I always hold the brake when I start the car so I would imagine that I would notice a problem if it was the brakes. The carb might need to be adjusted cause I haven't fiddled with the screws at all. It just seems to run so well when I drive it. I can't imagine the carb being too far off