Author Topic: TH350 or TH400???  (Read 1545 times)

Offline RebelBoy

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TH350 or TH400???
« on: May 19, 2021, 12:52:17 PM »
I’m restoring a 87 Chevy and about to change the engine out to a 355 that my father gave me. Right now I have the th400 but wanna know if I should keep that or switch to the 350. Ultimate goal is to put a little money into aftermarket parts but don’t have plans of being on drag strip. Any input appreciated.


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Offline LILT77

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Re: TH350 or TH400???
« Reply #1 on: May 19, 2021, 01:48:16 PM »
If you already have a TH400 and it's working fine then keep that and put the money you would have spent on a 350 into the engine or rest of the truck.
77 C10/Big 10 Cheyenne "Old Blue"
81 C2500 Sierra Grande "Gramps"

Offline VileZambonie

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Re: TH350 or TH400???
« Reply #2 on: May 19, 2021, 03:47:27 PM »
700R4
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline RebelBoy

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Re: TH350 or TH400???
« Reply #3 on: May 19, 2021, 07:48:22 PM »
If you already have a TH400 and it's working fine then keep that and put the money you would have spent on a 350 into the engine or rest of the truck.
Kinda how I was feeling after talking to some today


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Offline JohnnyPopper

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Re: TH350 or TH400???
« Reply #4 on: May 19, 2021, 10:53:04 PM »
The difference between the th350 and 400 is measurable, but if you're not into drag racing, you would benefit from the Overdrive feature of a 700R4.

They are gas guzzlers after all!!

I think there are certain year ranges that you want to select. See others for such info.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Sinister.454

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Re: TH350 or TH400???
« Reply #5 on: July 17, 2021, 08:42:19 PM »
I'll gladly accept the fuel cost for the privilege of driving a turbo 400 powered TRUCK!
Who buys a TRUCK and wants good mpg? :-X

Offline JohnnyPopper

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Re: TH350 or TH400???
« Reply #6 on: July 17, 2021, 11:32:40 PM »
I think the question is: Who buys an OLD truck and wants good mileage?

There was a day when it mattered.... ::)
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction