First place I visited yesterday couldn't do it they said, their pipe machine won't make those types of bends they tell me. I'm not asking for 90's, but I'm not an expert on it either, just showed them which route I wanted it to go and they said nope.
2nd place (only other place here in this small town) said they weren't sure, but they'd try.
I'm sure you have some place that can do this without issue. Years ago (likely nearly 18 years as I recall) my then supervisor (and good friend) had a 1970 Chevelle SS that he bought new originally. He ordered it (because his wife wanted White interior with a bench seat as they were expecting their first born) in red with black SS stripes, 396 with a 4 speed, white interior with a bench seat. He drove it for the first year he had it, then used it only in nice weather as they got a daily driver for other days. He hadn't had it out for a few years (this was around 2000) but when I built a 1967 GTO clone (no badges, just all the good stuff, still had Tempest lights and such) he got the bug. He had the engine rebuilt from the standard 396 to a mid 500 horsepower pavement pounder. Now, mind you... this was all naturally asperated and carbureted to boot. He needed a 3 1/2 inch exhaust thru 2 chamber Flowmasters to make it breath right. The shop he went to bent the pipe above the axle and also "flattened" it. Basically it was still the same 3 1/2 inch, but was oval shaped and then arched over the axle. It did not impede the flow, and the sound was awesome!
All that and 6-9 MPG depending on driving styles (on 105 race gas)…… and yes... he still has it with (last I knew) near 70K actual other than the changes. I asked him about whether he'd sell it for the right price..... he said that will be something to ask the estate directors. Until then, No.
Sorry for the long post.... just hoped to share a backstory that I thought was along the same issues.