I have re7s on the front of my 92. i had to notch into the frame to get em to fit. the bigger bag rides like a dream! it takes alot more cutting but it is worth it
the only thing that might hit is the upper ball joint and thats only because the bag is pretty far out from the frame. 7's would be a pretty easy fit really...
I have 7s on mine. I notched the frame an inch to recess the bag. Running slams helps because they balloon less and you can tuck the bag farther in the frame.
if you look at www.myspace.com/candoinstalls they have a full install and they use 7's. he used some 5 inch pipe and cut it in 1/3's i guess and used that for his "frame recess". it looks stupid clean and actually is like that for a reason.