Looking for a pair of 72 350 dual exhaust manifolds in good condition.

 

Olds didn't produce specific dual exhaust manifolds for the small- blocks. 69-74 350 single and dual exhaust manifolds (exc LH 69 350 4-barrel) are the same. All the factory did for DE applications was blank off the crossover port on passenger side manifold and connect LH exhaust pipe to LH manifold in place of the crossover pipe.

Some LH have heat riser valves.

Didn't Thornton make some true-dual cast iron manifolds for small blocks?

 

They don't exist as Rocketraider stated.

Even the legendary W31 and its high performance 350 used the same as all 350s and just capped off the crossover.

 

There are Thorton ones from many sources. Guess Ill go with those. Was the crossover for the intake? If I get the Thorton duels it will eliminate the crossover in the intake?

 

No. The exhaust crossover we're talking about runs from the LH exhaust manifold outlet, under the engine oil pan, and connects to a port on the passenger side manifold. Exhaust from both cylinder banks combines in the passenger side manifold and then out to the single exhaust pipe.

If the LH exhaust manifold doesn't incorporate a heat riser flap, it may take a little longer to open the choke due to less flow through the intake manifold heat crossover passage. But I've never noticed much difference in engine warmup between cars with heat risers and cars without it- unless the thing sticks closed, in which case the engine's gonna overheat.

Chrysler Parts Division had the best heat riser valve solvent of anyone. It worked.

 

PM sent

 

Looking for a set of these since they are out of stock. If anyone bought a pair and did use them message me.

https://www.inlinetube.com/products/inl12055

 

https://www.thorntonmusclecars.com/p...aust-manifolds

 

PM Sent