ART T

Were duals offered on 1964 Cutlass's? Did it require different manifolds?

svnt442

All SBO manifolds used a crossover pipe and thus there was a cap used for dual exhaust setups. If you want dedicated dual exhaust manifolds Thornton makes them, but they were never offered from the factory.

http://thorntonmusclecars.com/produc...aust-manifolds

joe_padavano

You do know what the "2" stands for in the 1964 442, right?

1970-W30

You need one of these to block off the exhaust port on the passenger side when changing over to dual exhaust. Or you can cut, crimp and weld shut the no longer used crossover pipe. The factory used this block off plate on the dual exhaust cars. I have a spare block-off plate if you are interested. $25 + $5 for shipping.

farmer52

PM sent

Bfg

I believe the 2 on the 442 meant 2 hands on the steering wheel.

oldsconv

Wait, I thought the 442 was a 442 cubic inch engine

Just kidding, we don't need to start that thread again......

Koda

So there was no crossover on Olds duals?

Charlie Jones

And now to answer the OP's question; According to the 1972 Olds master parts book;
Group 3.601 Exhaust Manifold
64-70 F-85 W/ 330,350 eng. R.H. 398704
64-68 F-85 W/ 330,350 eng. L.H. 393185

So yes , the manifolds are the same for single or dual exhaust . Since there is no mention of a difference .

Fun71

No crossover exhaust pipe running under the oil pan from one side to the other. There was a cap on the forward passenger side manifold port where the crossover pipe attached on the single exhaust systems.