exhaust troubles on 66 barracuda

68 340 passenger manifold has a rear outlet. 273 would have a center outlet, as would 71 and later 340s.

The rear exit manifold barely cleared my passenger side inner fender, even after I used a BFH to flatten a protruding section. Center outlet 340 manifold fit very well.

On the driver's side a 340 manifold may or may not hit the steering coupler. On mine, I switched to a power steering column and used an adapter to hook it to the manual steering box. That moved the coupler back out of the way.

There are potential clearance issues, but they are not insurmountable.

OP needs to visit another exhaust shop. Way too many can't handle anything that's not factory stock, unless maybe it's a Chevy or a Mustang.

Way back, one shop told my kid brother they could not possibly put a right side tail pipe on Mom's 64 Barracuda. So I drove to the shop with my 65 Barracuda which at the time had 2.25 inch duals. They were like, uh - uh - uh, maybe we could try. Told them don't think so, and we drove to a nearby shop which installed 2" duals (it was just a 273) no problem.

Another shop told me they couldn't put anything bigger than a 1 7/8 inch pipe coming off a slant six manifold. I wanted 2.25. Went somewhere else.

Brother took his 62 Dodge convertible, 440 powered, to a muffler shop that proceeded to put 2.25 inch exhaust pipes, and 2 inch tailpipes on it. I told him, you have to insist, can't just let them put on whatever they think will be easiest.

Back then, there was no TTI or other outfit offering a complete hi-performance exhaust system for our cars. I'd much rather get the kit and put it in myself than deal with some jackass at a muffler shop who thinks he knows more than I do.

However, unless you run headers, no one I'm aware of makes a kit for a first gen Barracuda running factory 340 manifolds. Accurate LTD if you want a hi-po single system for 273 manifolds. 340 manifolds, no. Unless someone recently began to do so.

Anyway, a good muffler shop (emphasize GOOD) should be able to fix you up. Might have to shop around. Also, as someone already said, if you don't have the right angle oil filter adapter, you probably need to get one.