This is an FYI:
I have a 700R4 in my '70 Cutlass 442 clone and I could never pull it in to low since the detent was for a three speed auto. Found the perfect solution at Shiftworks in Nevada. The kit for "70 cutlass is SC2312 fits 200 4R also, for $150, I didn't need the whole kit so the owner sent me the hardened detent, the arm for the tranny and 4 speed indicator for the console, for $75, which we installed while the console was still in, went through the glove box.
Nice job, a lot more fun now that I can hold it in low if I want to.