TheSamba.com :: View topic - Pros and cons of '72-'74 exhaust on late busses

Mon Jul 21, 2025 10:56 am

Hello! I'm rebuilding my '76 Riviera with a 2000 motor that needs a complete exhaust (stock) replacement. It appears that the exhaust manifolds (F-pipes) and crossover pipe is no longer in production. Due to that, and fewer pieces, I'm considering replacing everything with a stock '72-'74 exhaust system as everything seems easy to get.

I've seen it mentioned around here, but I can't find a definitive answer, so I started a new post.

What is the consensus, pros and cons, to doing this?

Thanks!

Mon Jul 21, 2025 11:10 am

Won't hurt anything as far as I know. But the F.I. set up cylinder heads do feature smaller intake & exhaust valves. Those & the F.I. camshaft choke off the breathing ability whether it's a '76 exhaust exchanger pair or an earlier set up.
The muffler flanges from the exchangers are also two-port discharge on each side versus the later true tubular flanges. <<Different muffler required

Mon Jul 21, 2025 12:10 pm

the real question will come down to the quality of the replacement parts.

Mon Jul 21, 2025 1:09 pm

You are basically building a '79 Federal bus with oval exhaust ports versus square ports.

Mon Jul 21, 2025 10:22 pm

It works great. The new mufflers are pretty good too; I’ve not used new T4 heat exchangers yet.

There’s probably a horsepower or two up for grabs by doing it, though you’ll gain a dB or two of exhaust noise as well. Most people think the tradeoff is worth it. Six fasteners instead of twenty nine? Yes please.

They pass the CA sniffer too.
Robbie