Badbanane what size is your exhaust, I don't remember what the stock pipe size is. 2", 2-1/4", or 2-1/2"? There are [were] a number of single in and dual outlet mufflers! Most were mounted transversly, [longer than the longitudinal variety, if I remember correctly] Camaro, Nova, etc. but they were out there. Try "Walker" and any other name brands you can think of. Harry
https://www.google.com/search?q=exhaust ... s-wiz-serp remember that the performance brands "tend" to be louder!
I'm not a hoarder I'm a preservationist 78 Monza Spyder (~Soon(ish +/- I guess) To Be 2+2 with Spoilers)