I have a 1966 cutlass convertible with a 330 in it (single exhaust, with a cross over pipe).

A local guy is selling a '1967 stock, dual exhaust pipes', claiming it will fit any big block.

This is a picture of what he's selling - the question is: can I bolt this up to my 330 exhaust manifolds?

Does anyone know if that set up can be used on my 330? I have never been able to find exhaust manifolds for the 330 that weren't designed to come together into a single exhaust.

 

That is because the factory never made a dedicated dual exhaust manifold for the SBO. All of the SBOs use the same manifolds - the dual exhaust setup has a cap on the right side crossover port, and the left side has an exhaust pipe connected where the crossover pipe would connect on a single exhaust setup.

 

You can make or buy a cap. You may have to shorten and/or mod the down pipes as your engine is an SBO and the exhaust is for a BBO, there is a difference in height between the 2.



Thortons makes an aftermarket dual exhaust manifold for your car.
http://thorntonmusclecars.com/produc...aust-manifolds

 

First, your 330 isn't a "big block". This means that the exhaust ports are lower relative to the frame than they are for a BBO. Those pipes may or may not bolt up without modification. It depends on which BBO manifolds it was designed to fit. The "fits any big block" likely REALLY means that they fit any big block with W/Z manifolds, which was NOT all of them. Sellers are notoriously mis-informed (as are many aftermarket parts vendors...).

Also. since those pipes are almost certainly designed for a 1968-72 A-body 2dr with the 112" wheelbase, they will be 3" too short for your 66 with a 115" wheelbase.

 

I believe the pipes are 2 1/4 inch for the BB and the SB 330 2 inch pipes. The flanges may not work on these pipes due to larger diameter. The block off caps they sell are for a SB though and wont fit the BB Olds exhaust manifold.

 

I guess the simple answer then is they can be made to fit. If they came out of a 67, they will fit your '66 and be a very close fit but they probably won't be a direct bolt-in fit. You would have to cut them anyway to get them in without pulling the rear end so you can shorten or extend them as needed. The next question is how much trouble would it be to connect them to your manifolds. As tempting as those are, you may be time and money ahead to get a new, bolt-in exhaust from Summit or some other aftermarket seller.

 

67 SBO's came with single exhaust, all piping was 2"

EXCEPT Dual exhaust was available with the 4 barrel high compression engines.
For these dual exhaust applications, the main exhaust piping was 2.25" and the tail piping was 2"

Hope that helps.
~J

 

You might consider taking your passenger's side manifold to a local welding shop to have the crossover port welded permanently closed. A cap may eventually leak. Also, I suggest taking your car to a local exhaust shop to have them price a set of duals for you. You would be ahead of the game vs. buying a set of pipes that won't fit and need modification. Plus, a local craftsman is bound to offer some sort of warranty on their work.

 

Frankly, there's a bigger risk of the welding shop cracking the cast iron manifold than of the cap leaking. Use Walker Acousti/Seal P/N 35959 to ensure no leaks at the metal-to-metal joint between the cap and the manifold (and between the pipe flares and the manifold ports).