I have an 87 caprice wagon and I am changing from a 307 olds to a Chevy 350. I need to upgrade the exhaust which is already a true dual 2" exhaust. I want to put in 2 1/2" exhaust, but was told by an exhaust guy that 2 1/2" won't fit over the rear axle. The car came with 2 1/4" and seemed to have ample space.
Has anyone ever hung 2 1/2" under a B-body car or even heard that you can't fit 2 1/2" over the axle?
For right now I am just bolting a set of Purple Hornies to the headers but I think that sound violation tickets will be a slight possibility. I also don't mind sticking the exhaust out in front of the rear tires, if that is even feasible in this car.
Any info would be appreciated.

Thanks  

I can't imagine why the extra 1/8" on either side of the pipe would effect it's clearence, at least not in a way a decent exhaust shop couldn't easily make work.  What I really wanted to do is call you a quitter for giving up on Olds power and going Chevy

Ever find out what was wrong with the 307?  

^^ He's forgiven...its a Chevy car

As for the exhaust question...I HIGHLY doubt that it won't fit...it probably has more to do with the exhaust shop not WANTING to do it.  Supposedly, 94-96 Impala SS tailpipes will work...but I have not tried it myself.  

I haven't given up on the olds. I just gave my 17 year old sister a 84 Buick Electra Wagon, which she Loves. I was going to originally take the 5A heads off of it an swap them with my puny 7A's. but when the brakes let go on the windstar she was driving and she hit a tree I thought I'd give her the Buick
So we have been puting the buick back together but now that  my wagon is getting a 350 i can put my 307 in her car.
I know that cylinder  #5 is dead and only has 20 psi and it will start and run but it blows a LOT of smoke which I was told is water vapor.  Luckily I had Golen's Engine Service build that motor for me and at the time he had a lifetime labor warranty on his engines. Even though I bought that engine about 6 years ago and have beaten the crap outa it for 150K+ miles he is more than happy to stand by the warranty.
So in the end I haven't given up on the 307 it's just going to put between a new set of fenders to make another young gearhead happy for as long as it served me.  

Water vapor, no compression, reaks of a blow head gasket!  Glad to see it going somewhere, it's nice to see pride in an engine, and even nicer that an engine builder would stand by his warranty!