Exhaust Manifold questions

[CandianRunner69]

Hi Everyone,

I have a question based on what an old Mopar fella told me just last night. I have a 69 Roadrunner with a 440 RB block. My friend noticed that the drivers side exhaust manifold was the larger 440 (Correct piece), while the passenger side was a smaller manifold from a 383. Now he has a proper 440 set for me to purchase. I have 2 questions.... first... is there a difference in the manifold to exhaust pipe connection location? Will I need to tweak the exhaust in order to reconnect? 2nd question... with the mismatched manifolds, could this cause a pressure issue in the crankcase? I've been experiencing issues with pressure pin holes in my valley pan. I still have to do a cylinder leak test to check for my seals. Any thoughts would be appreciated.

 

[Red63440]

Are we talking HP manifolds and if so what years?

 

[toolmanmike]

Hi Everyone,

I have a question based on what an old Mopar fella told me just last night. I have a 69 Roadrunner with a 440 RB block. My friend noticed that the drivers side exhaust manifold was the larger 440 (Correct piece), while the passenger side was a smaller manifold from a 383. Now he has a proper 440 set for me to purchase. I have 2 questions.... first... is there a difference in the manifold to exhaust pipe connection location? Will I need to tweak the exhaust in order to reconnect? 2nd question... with the mismatched manifolds, could this cause a pressure issue in the crankcase? I've been experiencing issues with pressure pin holes in my valley pan. I still have to do a cylinder leak test to check for my seals. Any thoughts would be appreciated.

View attachment 1172826

If you can get some casting numbers you can see what they are.

 

[CandianRunner69]

Are we talking HP manifolds and if so what years?

Yes HP manifolds. 68 Manifolds for a 68 RB block

 

[CandianRunner69]

If you can get some casting numbers you can see what they are.

I'll try and get in the crevasses to check and see..... thx

 

[dadsbee]

383 and 440 HP manifolds are the same.

 

[CandianRunner69]

383 and 440 HP manifolds are the same.

ok... thx... the only thing is the drivers side looks like a larger bore and flares out from side of cylinders while passenger side is visibly smaller and much tighter to the cylinders. I'll have to get some pics...

 

[dadsbee]

'68/'69 HP manifolds

 

[4mulas]

First things first just take a picture of the passenger side and the drivers side. Maybe someone put a log manifold on the passenger side and this answer will be a pretty easy one

 

[Don Frelier]

If I remember correctly the passenger side lined up on mine when I switched from the 66 log style to the 68/69 manifolds.
So you might get lucky.
But no I really dont think that has anything to do with a valley pan leaking.
You have excessive crankcase pressure or some other issue.

 

[CandianRunner69]

First things first just take a picture of the passenger side and the drivers side. Maybe someone put a log manifold on the passenger side and this answer will be a pretty easy one

This is somewhat new to me. What do you mean a "Log Manifold" ?

 

[toolmanmike]

This is somewhat new to me. What do you mean a "Log Manifold" ?

You would know it if you see it, all the ports are inline along the valve cover rail then they dump. Not like a manifold with individual ports.

You need to take some clear photos, post them here along with the casting numbers. Otherwise all this discussion is going nowhere.

 

[Red63440]

A log manifold looks just like that. It’s a straight non performance manifold used on standard engines.

 

[4mulas]

You need to take some clear photos, post them here along with the casting numbers. Otherwise all this discussion is going nowhere.

This

 

[CandianRunner69]

Thanks Gents.... I'll grab some pics tonight...

 

[CandianRunner69]

Ok... so after taking some pics last night and doing a little research on the casting numbers..... (2806900 and 2843992-1) I have found that I don't think anything is wrong at this point. The passenger side does fit much tighter to the valve cover than the drivers side. I'd be curious to the casting numbers that the old fella ahs that pointed this out to me.

 

[Don Frelier]

Those are the correct numbers.
So he was trying to sell you the same manifolds you already have?

 

[CandianRunner69]

Those are the correct numbers.
So he was trying to sell you the same manifolds you already have?

I'm not sure... I've asked for the casting numbers for reference. if they are the same then no biggy, but if they are in better shape than mine then the 100 bucks is well worth it.

 

[Don Frelier]

$100 is a deal they are typically 300- 400 USD
All forgiven then

 

[CandianRunner69]

$100 is a deal they area typically 300- 400 USD
All forgiven then

And that's in Canadian .... lol