318 manifolds ?

[hoosierdaddy]

I'm wanting to know if 318 manifolds will work on a 340 ? I have headers now but I think I want to go back to manifolds .

 

[goldduster318]

they do work, but A-body 318 manifolds are quite possibly THE worst flowing manifolds ever devised. Mostly because of the crap driver's side ones. They have at best 2" outlets. I would suggest against it

 

[bobscuda67]

You might have port mismatch leaks also.

 

[1967DartGT]

I've read that the magnum manifolds flowed nearly as well as the 340 manifolds but likely won't fit on the driver's side.

 

[hoosierdaddy]

Why am I not surprised . Thanks everyone

 

[340 Dart]

What car are they for?
Can you use 360 manifolds?

 

[tyler_s18]

You might have port mismatch leaks also.

what would port mis match hurt? my 360 is ported and i have the 318 manifolds on it

 

[Bill Dedman]

It will hurt exhaust flow and engine output. Might even affect exhaust valve life.

Sure, they'll bolt on and probably run okay at part throttle, but the're so restrictive compared with a good flowing system, that they're probably going to cost the engine 30+ horsepower.

Not a very good idea if you care at all about how the engine performs at full throttle.

 

[tyler_s18]

ok thats what i figured. i cant afford headers yet and dont want to hurt the engine lol but can deal with a little slower for now

 

[TT'74]

What year is your car, magnum manifolds fit my '74 duster with manual steering. If you get the '92-'93 manifolds they have 2.25 outlets too.