Hello fellow oldsmobilers.
I got a 1968 delta88 with singel exhaust system.
Is there any dual exhaustkits that just Bolts on the original exhaust manifold or do i have buy after market headers?
Best regards

 

Welcome. This question comes up regularly. There are no aftermarket headers made for these cars. The location of the steering box makes header design problematic, and since these cars are not popular to hot rod, there is no market for a header manufacturer to recoup their investment. You cannot run dual exhaust with the LH manifold for a single exhaust car. You physically cannot fit the pipe between the starter and the steering linkage. The factory used a special LH manifold on dual exhaust cars. These are reproduced. You must use one to run duals. The RH manifold is the same for single and dual exhaust. The factory just bolted a cap over the unused hole for the crossover pipe. The cap for the 350 manifolds does not fit this manifold, so you will need to fabricate a cap from the old crossover pipe.

 

If the car in question is a automatic column shift, you’ll also need to find or fabricate a half moon shifter rod to clear the new left pipe.

I believe someone has a design or specs for it here somewhere.

 

You are correct that factory dual exhaust cars had the "notched" shift linkage rod, however I converted my 67 D88 to duals using the repro manifold, and while clearance is extremely tight, the original straight rod does clear. Admittedly I have a reproduced set of exhaust pipes, so possibly that pipe isn't bent exactly the same as OEM. In any case, I'm converting to buckets and floor shifter, so this is a moot point for me anyway.

 

Thornton makes a shorty header if that helps you.
As far as a bolt on dual exhaust. I doubt it exists.
Not much for big cars out there. You're likely gonna have to have it made at an exhaust shop.
Good luck
Jim

 

Um, go back and read Post #2 in this thread. The shorty header will NOT work in the 65-70 full size cars. You can get a bolt-on dual exhaust system for the stock manifold shown in Post # 2 from several sources, including this one.

 

The Thornton is supposed to be a bolt on replacement for factory manifold. I could be wrong
I was considing them for a different application.
(Olds powered 2nd gen f body)
I went with Hooker supercomps and waited all last summer for them.

 

They are a "replacement" for the A-body manifolds. One more time, does the manifold in post #2 look anything like an A-body manifold? Here, I'll make it easy for you.




Note the dramatic difference in the location of the outlet.

The shorty headers will point directly at the steering box in a 65-70 full size. Have you ever even looked at one of those cars?

 

There are quite a few threads on our site about installing duals on the 65-70 B/C body. You can either get the reproduction manifold or modify a Toronado manifold. Come to think of it, I also think you can have dual exhaust by running both pipes back from the passenger's side. I believe my dad's (Oldsguy) 69 Delta 88 was setup that way before we modified the Toronado manifold. Here are a bunch of threads. Sorry there aren't any pics.

https://classicoldsmobile.com/forums...archid=4774918