RV with 440 - stock manifold or headers?

[Chris R]

The l/h exhaust manifold is shot on my Dodge RV 440 - it's not the standard car item but a manifold specific to fit the B series van body with the engine under the cab. I've learned on an RV forum in the US that it's designed to handle heat differently from the car manifolds as these engines can get very hot hauling big RV bodies up mountains, etc. (The RV manifold collects gases a bit lower down, to keep heat away from the valve cover gaskets, as I understand it.)

I'm looking for the correct manifold (if anyone has got one to sell? see pics below for l/h side), but failing that I'm thinking about headers (regular/car 440 manifolds won't fit anyway). Should I be worried about the extra heat headers would generate as I'm here in the UK? It's obviously cooler than parts of the US, and I'm not going to be trucking over the Rockies.

WhatsApp Image 2026-02-03 at 13.50.19 (3).jpeg (115.29 KiB) Viewed 850 times

WhatsApp Image 2026-02-03 at 13.50.19 (2).jpeg (85.95 KiB) Viewed 850 times

WhatsApp Image 2026-02-03 at 13.50.18.jpeg (111.65 KiB) Viewed 850 times

WhatsApp Image 2026-02-03 at 13.50.19 (1).jpeg (109.94 KiB) Viewed 850 times

Here's what a good one should look like - part number is 3830247F

Screenshot 2026-02-06 at 10.18.04.png (598.51 KiB) Viewed 850 times

[MattH]

I doubt the heat from headers would be an issue, they are thinner than cast manifolds so don't retain as much heat anyway. Duncan (Cannonball) Watts might have manifolds he has ALOT of Mopar spares up in Crewe. He doesn't get on the forum very often now, so best to call him.
07974 088375.
Watts Racing Transmissons.

[Blue]

Those manifolds must be fairly rare, I’ve never come across a set. Headers every time, I don’t see heat being an issue but with a decent 2.5” exhaust system you will see an increase in torque and HP, certainly a bonus on an RV, you might even pick up a bit of mileage…

[Chris R]

Thanks both - called Duncan but he doesn't have one. They are rare, but I thought someone might have salvaged an RV 440 for a car or truck project, and have the old manifolds kicking around. (That seems to be what happens to old RVs in the States, but perhaps people are less likely to scrap them over here.)

I'm thinking I might go with wrapped headers, but there's not much room in the engine bay so need to be careful sourcing the right ones.

[Pete]

I would imagine that Headers are the only realistic option, but I would not wrap them.

The wrapping, whilst being "Cool" on Hipsters murdercycles, retain the moisture and I have seen Headers literally fall apart in a very short time - it made the steel fall off in layers!

Your car, so your call.

Cheers!

[Chris R]

I would imagine that Headers are the only realistic option, but I would not wrap them.

The wrapping, whilst being "Cool" on Hipsters murdercycles, retain the moisture and I have seen Headers literally fall apart in a very short time - it made the steel fall off in layers!

Your car, so your call.

Cheers!

Would that happen with stainless steel? I wouldn't be doing it to look cool - they're buried under the floor so you can barely see them. That's why the heat can build up and cause problems - at least according to US RV forums. I'm not sure if that would be the case in our milder climate.

[Stu]

I wholeheartedly agree with Pete on the wrap.

I had a brand new set of TTI headers that were wrapped. When I came to overhaul the engine bay a couple of years later, took the wrap off and they were in terrible condition.

I’ll never use it again. I ended up getting them stripped and hot aluminium sprayed. Much better.

In my opinion, if you wrap them, you can look forward to replacing them in the near future.

[Chris R]

OK - wrapping is off the agenda then. I don't want any extra hassles.