I am switching out my standard ratio gear box for a quick ratio, is there anything else that needs to be converted or will they interchange OK?
Would I be better off just rebuilding the standard ratio? Thanks.

There are different sized shafts among the gearboxes. Be sure to get the same sized shaft on the new box.

Some in our group have used the 2.5-3 turn version from a 78-79 Firebird. Not sure about the shaft until I do mine, but they used a universal rag joint kit which had enough parts to match up. Part number at O'Reilly is 27-6510, and it's about 150 with the core charge.