I'm planning on taking the Lazy-Man's "dual" exhaust (as well as the glass-packs and crap welds it features) that was "installed" by the previous owner and promptly getting it as far away from my Olds as I can. In place of it, I'm planning on removing the crossover tube between the two manifolds and running dual exhaust the correct way, however I want bring back the car's OEM exhaust sound as much as I can in the process.

As such, I'm looking for a pair of good-condition mufflers and rectangular resonators from a '75 Full-Size to use in this project. If anyone has these (or knows where about I can find them) it would be greatly appreciated.

 

First, are you in an area that your car has to pass smog? If not:

Find a 71-74 factory transmission crossmember. It will have two humps for exhaust pipe routing and I think someone has said a crossmember from any GM B or C car will work.

Then have a competent exhaust shop fab the pipes using stock replacement mufflers and resonators.

If you can find a pair of W and Z dual exhaust manifolds you will have effectively duplicated the 71-74 dual exhaust system.

 

Thanks for the tip on the manifolds and crossmember!

The main issue I'm unable to find OEM replacement resonators outside of complete exhaust kits.

 

'75 was the first year for mandated catalytic converters on US cars, so You'll need '71-'74 as mentioned above. I should have a dual hump big car transmission crossmember. If interested, email me direct: drolds1@bellsouth.net. Thanks, Bob.

 

Got any part numbers?

 

Sadly I do not. While the mufflers are aasy enough to find new, I've been unable to find any photos of the resonators, let alone P/N s for them.

All I've been able to go off of is what the FSM shows, which are rectangular resonators mounted beside the fuel tank which have the exhaust tips on them.

 

The 73 B body w/455 used a resonator w/pipe p# 413952 RH, 413953 LH
Brett

 

Two '71-'74 Chev B tubular double hump crossmembers available. Southern NM metal, not rotten from inside out.

 

Since dual exhaust wasn't available for 1975, if you want duals with resonators, you'll have to use 1971-74 resonators.

Grp 3.702

1971-72, part # 409468, 2 required

1973 C (98) p/n 413954 RH, 413955 LH

1974 B&C w/455 and dual exhaust, p/n 416236 RH, 416237 LH

If you can find a pair of 416238 (generic resonator for 71-76 88/98 single exhaust cars) those will work too.

Sometimes the resonators' tailpieces are different length between 88 and 98 to account for differences in the trunk length.