Do they still make those things?? Unless they've changed, they had a limited life. First the fiberglass packing burned out, then the muffler rusted out from the inside out. In Michigan, they lasted for about two winters, maybe.
IMO, you're not working w/ a 70's era V8 muscle car (different engineering/performance) and it would probably sound like total horse doo-doo. Look into something a bit more practical f/ today's vehicles...aFE Power sells an entire line of exhaust systems for our trucks.
Advanced Flow Engineering, Inc. (aFe) produces high flow, high performance air filters & cold air intake systems for the automotive industry. Founded in April, 1999, aFe was created to address an obvious need in the automotive aftermarket industry: a lack of choice for a high performance...
Since the early to mid-80's, I've liked the "turbo mufflers" on 6 cylinder vehicles. No, they don't have the dual exhaust, v-8 Flowmaster (or similar) sound, but they do sound great. I've you've ever heard a 1987 Buick GNx launch with them, wow is all I can say. The GN's sound about as good too, but part of the sound of these may be the actual turbo sound mixed in.
Full disclosure, the GNX is my dream vehicle but they have gotten out of my likely price range. They made 547 of them and the cost has been going up exponentially for the past 15 years or so and now go well over $100k. I do have a 1983 Hurst/Olds with the lightning rod shifters. It has a 307 v-8 Olds motor and though it is MUCH slower than the turbo 6 of the GN/GNx, it sounds great with a pair of the same turbo mufflers (single in is split into two mufflers).
I refused to use Thrush or Cherry bomber mufflers even Back in high school.
I went with Cyclone Turbo Muffler as they were the leading edge stuff before Borla, Flowmaster and others came along.
I had to bolt right on the headers since I ran a full ladder bar rear suspension. They were quiet when I wanted them to be and loud when I wanted to be.
But the best thing now is stainless. My Pontiac is a 1985 and it is still on the stock factory exhaust. Pontiac did a great job on the Fiero exhaust. They really made a 2.8 V6 sound like a V8. I often get asked if my is a V8 and I tell them no.
Okay here goes all my street cred, but I have to share!
Back in the 80s my older brother and I thought that putting a Thrush glasspack on "our" car would be awesome. However, I have to admit that we were driving a 1978 Plymouth Fury 4 door, with a straight-six and a 3-speed auto. The glasspack didn't add anything to the car, in fact as the younger brother, I just nodded and agreed that it sounded way better!
It did however have cragars all around with 12" wide slicks on the rear and air suspension that we kept filled to the max!