350 Exhaust Manifolds

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HotRodPC

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A older neighbor was telling me this type of exhaust manifold flows as good as a header. I was wondering if anyone else could confirm or deny that for me? I've always used headers. Being I'm preferring quieter rides now days, I was thinking if I could get the right matching one, I'd go ahead and give them a try. Especially since I have the pipes to match the manifolds.

Anyone have a right side in this style for cheap???
 

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bucket

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I doubt it's as good, just better than other manifolds. I think the big block version is probably a little closer to a header in design.
 

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I wish I had the right one too. I wouldn't mind using it on a stock 4bbl 350. The left was still bolted to the exhaust pipe in the bent frame truck, but whoever pulled the engine, took the right side with it.
 

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It seems to me that these manifolds was used in the pickumups just before the TBI systems come out.
I remember seeing those on the 4.3 engines that was in the DOTs pickups, when the Duo~Jet carbs was in use.
Not real sure but I`m a thinking that was the vintage.
I too thought the same thing about them being about as good as headers.
 

HotRodPC

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You'd think it's obvious they at least flow better than most standard OEM manifolds as we know them. If anyone has a right one let me know. You can get the standard OE type for like $89 each new in a dorman brand. For these type in Dorman they are $210 each. So I won't be buying any new, but would like to use them if possible. I'd use headers before I spend $210 + tax and shipping for one.

Maybe I should put this left one on eBay and buy me some cheap headers. They should still be quiet with those OEM mufflers.
 

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I do not recall the DOT ever having any leakage or loosening bolts with them types of manifolds as in with headers.
 

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Those are the LT9 3/4 ton 350 manifolds in 85/86.they are smoother and less turbulent on the inside opposed to the cast manifolds. They are still available through Dorman.
 
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HotRodPC

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Dorman's are $200 - $210 EACH depending on where you look, but I'm not paying that. Manifolds are $12 each at PAPart, so I'll just have to wait and check there from time to time. I'll find one eventually that fits my loser lowlife budget. That'll give me an exuse to have to to PAP more often than I've been going. C'mon Spring time !!!
 

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I will watch for one for You too, from Pacific Steel and Recycling. They get in quite a few vehicles and dump the engines into this big old half of a tank looking thing.
I keep going back and checking the transmissions bin looking for a NP203 that come from behind a TH400, I am needing the input shaft/gear, the sliding collar and the low range gear. Mine is fugged up, ca`nt even hold it in low range.
Also looking for one of those very elusive NP205 to a TH400 adapter. I have the T-Case but the adapter is for a TH350, and, mine has the smaller input bearing, IDK if that`ll make a difference ???
 

HotRodPC

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I will watch for one for You too, from Pacific Steel and Recycling. They get in quite a few vehicles and dump the engines into this big old half of a tank looking thing.
I keep going back and checking the transmissions bin looking for a NP203 that come from behind a TH400, I am needing the input shaft/gear, the sliding collar and the low range gear. Mine is fugged up, ca`nt even hold it in low range.
Also looking for one of those very elusive NP205 to a TH400 adapter. I have the T-Case but the adapter is for a TH350, and, mine has the smaller input bearing, IDK if that`ll make a difference ???

The NP205 to Th400 adapter is not all that elusive. Not common, but they're out there. The one that is elusive is the one for the Round Pattern for the 4L80-E. I'm also looking for a Round Pattern NP205 with 32 spline input. Then I'm going to put a notch in the round adapter part of my A883 so I can run a NP205 behind the A883. Of course I'm going to run it with the NP208 I have for it now, but until I get the ultimate NP205, the 208 will be fine.
 

bucket

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Dorman's are $200 - $210 EACH depending on where you look, but I'm not paying that. Manifolds are $12 each at PAPart, so I'll just have to wait and check there from time to time. I'll find one eventually that fits my loser lowlife budget. That'll give me an exuse to have to to PAP more often than I've been going. C'mon Spring time !!!

But if you find one there, chances are good both sides will be there, so you will get both sides because they are good and cheap. Then you will still have the odd one and be on the hunt for a match so another truck can have a set, but you will likely find another pair...

I will watch for one for You too, from Pacific Steel and Recycling. They get in quite a few vehicles and dump the engines into this big old half of a tank looking thing.
I keep going back and checking the transmissions bin looking for a NP203 that come from behind a TH400, I am needing the input shaft/gear, the sliding collar and the low range gear. Mine is fugged up, ca`nt even hold it in low range.
Also looking for one of those very elusive NP205 to a TH400 adapter. I have the T-Case but the adapter is for a TH350, and, mine has the smaller input bearing, IDK if that`ll make a difference ???

You would need the adapter, larger input, larger bearing and retainer, and also have the case machined for the larger bearing. It's not cheap or easy, may as well just find a setup for a th400 and sell what you have to recoup some cost.

The NP205 to Th400 adapter is not all that elusive. Not common, but they're out there. The one that is elusive is the one for the Round Pattern for the 4L80-E. I'm also looking for a Round Pattern NP205 with 32 spline input. Then I'm going to put a notch in the round adapter part of my A883 so I can run a NP205 behind the A883. Of course I'm going to run it with the NP208 I have for it now, but until I get the ultimate NP205, the 208 will be fine.

I understand the notch, but what will the t-case shifter bolt to?
 

HotRodPC

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I understand the notch, but what will the t-case shifter bolt to?

I had planned on Twin Stickin' it. Might have to go with a cable operated twin stick if I don't figure out a way to make a bracket.
 

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