Need recommendation on exhaust system for 425

[Guest connl]

I have a 1965 Dynamic 88 convertable with a 425 engine. I'm new to car restoration. What kind of exhuast system is recommended that won't destroy car value? Can I install headers and dual exhaust or is that a bad idea. Car has single exhaust currently.

[rocketraider]

Duals were available from factory so don't worry about destroying the value. You'll need the dual exhaust LH manifold to do it correctly; the single exhaust LH manifold poses some challenges routing the headpipe around the starter and lower control arm. The correct S manifold is available reproduction, and you'll have to alter the shift linkage to clear the new manifold and pipe. Yes, Oldsmobile had different shift linkage for 1965-70 single exhaust and dual exhaust cars. The crossover port on the RH manifold will have to be capped, same as factory did on factory DE installations.

I <span style="font-weight: bold">think</span> you can get headers for the 425/B-body but don't quote me. Between initial install headaches and the inevitable leaks, anymore I think they're more trouble than they're worth.

[chocolate rocket]

I have a '67 delta88. the steering box got in my way and so did the starter. so I'm going to try a high torq starter and avoid speed bumps...lol

[joe_padavano]

Manifolds vs headers is a constant debate on just about any forum. Ultimately, is the hassle of headers worth the extra performance to you? I prefer headers personally. In either case, get a good 2 1/2" exhaust system and high flow mufflers. Pypes Exhaust makes a very good stainless exhaust system (use their Cutlass system and cut to fit) with either header connectors or down pipes for stock manifolds. The B-body dual manifolds will require some custom bends to mate up, however.

Muffler sound is another personal choice. I'm waaay too old for Flowmasters. The Walker Dynomax turbo mufflers are consistently among the highest flowing in magazine tests and have a nice throaty sound that is not obnoxious. I use the 14" Walkers but the also make a 21" version that should be even quieter.

[Oldsmaniac]

To my knowledge there are no off the shelf headers available for your car and you would need custom headers made to fit. I have 3 66 full size Oldsmobiles all with dual exhaust and I use the factory style 2 1/4 inch pipes with stock mufflers and resonators just like the factory did. The cars are very quiet just the way I like em these days.

[Guest JRZYBOB442]

Kooks Custom Headers Makes a set for your car.

http://www.kookscustomheaders.com/vehicle.php?cname=Headers&year=1966&make=Oldsmobile&model=88

[gumpy]

I just put a dual exhaust system on my 65 olds 98 convert and had to buy a new replacement left side exhaust manifold. Th exising one dumps right into the steering box and a pipe could not be bent to fit. I bought a replacement from a place in Pa and it fit perfectly,,,$150 it cost me. If you need the name and address of the place let me know and I will dig it out for you. bob in Ohio

e mail gut@glis.cc