383 vs. 400 exhaust manifolds

[Joeladam02]

Can anyone tell me the difference between the two?
Do the 383 exhaust manifolds have better air flow?
The car currently has a built 383 with 400 exhaust manifolds, but I am leaning towards replacing them with the correct 383 manifolds.
Just wondering what the real differences are, and anything that I may run into in the process.
Thanks!

 

[PP1RT]

About the same. Get some HP manifolds if you want cast iron and a little better performance. Otherwise step up to headers and watch the flange thickness. The good ones have thicker flanges where they bolt to the head.

 

[Joeladam02]

OK. I think I should clarify with casting numbers, because I'm not even 100% sure those I have are matching.

The manifolds that came on the 400 are:
Left - 3830800
Right - 4041463

The manifolds that came on the 383 are:
Left - 2463107
Right - 2532464

Are any of these any good as a pair / do they match one another?
Are the ones from the 383 worth switching to?

Thanks.

 

[super-bee_ski]

I personally believe a pair of 383 HPs or 440s would flow better than the 400s
But: Were talking a small percentage here.

If you want to flow better get TTI headers
But, that is costly.

 

[Joeladam02]

Thanks for the advice.
Has anyone ever tried these repro HP manifolds?
http://www.ebay.com/itm/NEW-Mopar-1967-69-B-Body-Big-Block-HP-Right-Exhaust-Manifold-/161805533462?hash=item25ac5c8116&vxp=mtr
I'm wondering what the fitment may be like.

 

[Cranky]

By the time you buy both sides, the TTI's start looking pretty good but if you're bent on stock type exhaust, you should be able to find good used ones for much cheaper than the ones on Ebay. A buddy of mine has some but getting him to turn loose is the killer.....he'll never use them but someone might be able to once he quits the earth.

 

[PP1RT]

I probably have some HP manifolds around here if you want to go that route. If you are interested pm me and i will check.

 

[monaco66coupe]

the Old log manifolds work, ok. Hp manifolds, 68-70 would be nice to find. Past that, TTI'S, and a group of others.what year car are you working on?

 

[Joeladam02]

the Old log manifolds work, ok. Hp manifolds, 68-70 would be nice to find. Past that, TTI'S, and a group of others.what year car are you working on?

1970 Road Runner with a '66 383.
Leaning towards the HPs, as I've heard the headers never really seal correct, cause a lot more heat, and have an awful drone during street driving.
How much of that is true?

 

[monaco66coupe]

I for one agree with all the above. I may have a set as well, But any 68-71's will work for you.

 

[jeepers007]

Wasn't there a magazine article where they dyno'd hp and regular manifold and found only a very small horsepower difference?

 

[monaco66coupe]

maybe, I have logs on a 383 HP engine, and my other 383HP car with the HP manifolds runs a lot better. This is just my experience.

 

[Joeladam02]

Well, I guess I'm on the market for a good set of HPs. I'd rather buy from someone here than eBay.

 

[PP1RT]

If you can find some nearby shipping would be cheaper because they have a little heft to them. A set of ceramic coated headers are lighter,hold down the heat better than painted and breathe better than cast iron.Get a set with 5/16" flanges and quality gaskets and they seal fine.

If you cant find HP manifolds nearby i have a set or three laying around. Just shoot a PM if you need some. I "think" i may even have a set of 70 castings.

 

[tommyg29]

So, the 383, 400 and 440 manifolds are interchangeable? Curious about a 1972 400.
Thanks.

 

[monaco66coupe]

all Interchangeable. my 74' 440Hp engine has the Manifold part numbers on the exhaust of the 72'. They obviously were using up leftover parts.

 

[Joeladam02]

Still looking for a good used set of 383 HP manifolds.
PM me with cost + shipping to 16248.

 

[tallhair]

Still looking for a good used set of 383 HP manifolds.
PM me with cost + shipping to 16248.

Now that you know what you want put up a wanted to buy WTB ad in the Wanted Ad Forum

 

[Dennis H]

Just get your wallet and TTI's. Lighter, cooler, good fit. 9 years of reliable performance and they have been slammed scraped etc. Get the ceramic coated.