sidepipe clearance needed

I found a "windfall" concerning sidepipe installation when I used another's advise on inserting Car Chemistry Inserts into the J-pipes. The CC's wouldn't slide in due the conflicts with the flange on the J's. I used a power band saw to cut the J's in half. I used a Pep Boys 2.5" exhaust pipe union to put the two J's back together. I only torch welded one end to one half of the J's til I got the pipes lined up. Then I tack welded the union to the other J, took it back apart and finished the welding. The exhaust pipe union set-up let me twist the J's and attached side pipes as much as needed to make them level, etc. I found this a bit more accurate and easy that ovaling out the flange bolt holes (in my opinion). Eddie