Cylinder Head exhaust port size

[Weatheralls Auto]

Looking for Cylinder Head exhaust port size of 3500 COMPARED TO 3400?

Any difference? Does 35mm or 1.32" width sound correct for a 3500?

Didn't see these listed in the Specs.

[Weatheralls Auto]

Any1 have some heads they can measure?

[bszopi]

There is a difference. I thought there was a pic somewhere around here comparing the 2, but I haven't found it in the breif looking I did.

[Weatheralls Auto]

I have 2 exhaust manifolds here, one from a 3400 Van and one from a 3500 van,
the 3500 manifold is def bigger, but the 3400 manifold matches the port on the head much better.

There is someone selling Turbo manifolds from a Turbo GP, that "hogged" out the ports to match a 3400.

Just wondering if they will be good for me and the 3500, stil can't find the pics

[IsaacHayes]

You don't want the manifold to match the port on the head. You want it larger so that has an anti-reversion effect so you don't get gasses going back into the head.

[DefEddie]

You don't want the manifold to match the port on the head. You want it larger so that has an anti-reversion effect so you don't get gasses going back into the head.

Yeah,you want at least a millimeter over the head port size-never perfect match on exhaust side.