2 types of Doug headers for early 64 to 66 Valiants ??

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Mopar64340

Mopar64340

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Hello Guys.

So i recently installed my headers. And holy crap either I got a bad set or they arent meant for a 10.5 bell housing on a 340 in a 1964 plymouth valiant with torsion bars !

See my pictures below. Jegs has one set and classic industries has another. Im so confused ! I bought the jegs ones. Thoughts ??

Anybody know the difference ?

Screenshot_20240213_222211_Chrome.jpg


Screenshot_20240213_222411_Chrome.jpg
 
They are both the same but the coating is different.
Also Doug’s are made for the factory smaller bell housing and clutch 9” I believe in the earlier a bodies. Even in my 66’ 273 with a center console 904 it is stupid tight.
 
What did you get, D450s or D454s? D454 is only for use with the Alter-K-tion K frame.
If you got the D450 (or D450-B), this is direct from the Doug's website (and is in the installation instructions):
1707921983393.png


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They are not the same, look at the pics.
 
You can't always go by the photos. I'd call CI and ask them what the manufacturer's part number is for the ones they list. I'd bet they're the exact same headers. To my knowledge, Doug's only sells one set of headers for early A's, but there are variations depending on the coating. If it's black, there's only one - D450B. I could be wrong though.
 
When I did mine I had fitment problem as the car had to thick of motor mounts. The previous owner had installed the wrong motor mounts when he swapped the 340 in the car. He ended up putting the old 273 exhaust manifolds back on. Once I had purchased the car I tried to put the Doug's in (D450) and no way could they be bolted up. I ended up ordering Schmuker engine mounts and it was 90% better but still had a lot of work to get the linkage in with the brewers parts. Just re-centering the engine and resetting the angle of the 90 oil filter adapter was the next problem to get it to work. This car also had the 10.5 bell and mini starter.

Not sure if this is your problem but it might be something to look at and my now 65 Barracuda is running TTI's with the same 10.5 bell and it was the same amount of work to get it all to work.
 
In the early 70s I acquired a 1965 Barracuda that had been an SCCA A-Sedan racer since new and had a history in the overlaid "Pro" Trans Am series. Of a few exotic components and mods it had a set of full length under-chassis headers made by Doug Thorley. The company has gone through permutations of "Doug's" and "Thorley" and so forth since the 60's and I have not tracked or kept up. But I can say that the race car set I had were a nightmare for my street adaptation. The bellhousing was a beefy stamped scattershield and the driver's side header consisted of a section installed from underneath with two upper tubes inserted separately down from the ports above. Clearances around the steering linkage and starter were fractions of an inch. Street driving stressed the starter to the extent restarting when hot would often fail for the baked starter. In the day of being able to buy sheet asbestos I fabricated an aluminum plate and asbestos sandwich shield that helped but didn't totally mitigate hot start. I know my experience isn't wholly relevant to current product advice but I have one comment resulting from my 50 yr old episode. I have built a number of hot motor early A-bodies since and have concluded that you can't go wrong with a set of factory 340 manifolds. I came to conclude that the theoretical performance advantage of full length tubular headers isn't worth the fitment brain damage. One of my most satisfying and seat of the pants fastest variations used iron manifolds. There are lots of other engine tuning variables that will kick *** without needing sheetmetal pipes.
 

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Valiantjim said:
In the early 70s I acquired a 1965 Barracuda that had been an SCCA A-Sedan racer since new and had a history in the overlaid "Pro" Trans Am series. Of a few exotic components and mods....
Click to expand...
go on... we're listening...

(and demanding more pics)
 
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