i haven't measured it yet, but i gave them the measurements you gave me and i bet they took atleast a quarter inch off(no wonder they didn't charge anything), and it was tough getting the old back in, but i managed, allthough stupid me forgot about the coolant temp sensor on the bottom of the intake and broke that, but i did the gaskit while i was at work so i just called up robbins and got a new one...the old gaskits didn't look to bad, but i really did it as preventative maintance and to get that dex crap out, i've been 90 miles since i did it yesterday and everythings so far so good...it took me about 3 and a half hours but i also was at work and had air tools to take it apart and a lift) and i cleaned everything spotless...thanks for all the information and help

Glad you were able to get the old stovepipe back in. While not the best, you will still have a decent .065" gap between the pipe and that nice, new, metal heat shield. Wow, I can't imagine a machine shop that couldn't take a .750 OD down to .625 without screwing it up. Not only should they not have charged you; if they had any integrity, they would have turned you a new one from 5/8" stock, and only charged you for the originally agreed price. Oh well, you still have a fix for your car that is better than 99% of L36s out there. Even with the bigger 5/8" stock pipe, as long as you keep air pockets out of the coolant and keep it running cool, you really should not have to worry about the UIM again. Glad you got it done.