348 Transmission ?

Hello everyone. Just signed up for the forum this morning. Have to say the website is awesome!
I picked up a 348 about 6 months ago. It was pulled out of a 1958 Impala Wagon.
I want to put in into my 1929 Ford Coupe I'm building. I'm not very familiar with these engines and was wondering what type of transmission would bolt-up? I would like to run a Turbo 350 or 700R4 if possible. Any suggestions would be greatly appreciated. Thanks!


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Supporting Member 6
a 348 is internally balanced, so most any trans and flexplate will fit and work. if you are starting from scratch, and like to cruise, go with the overdrive. not sure if that block has starter bolt holes though.


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walkerheaders said:
.. so most any trans and flexplate will fit and work..
The machinist working on my engine tells me that the 348/409 have a different flange on the back of the crank - that "any" flexplate won't work - that it needs a flexplate specifically for the 348/409 cranks. (?)

'Spose he's just telling me that so he can sell me an expensive flexplate?

I know I need to select my torque converter according to the tranny, but can I use a small block flexplate?

Are you sure?

Fathead Racing

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Supporting Member 7
Flexplate ?

I can't remember where I got my flexplate, it is a flexplate from a 350 turbo, but I do remember I did not have to do anything to it to make it fit!. It is the 168 tooth flexplate, did I get lucky?


All I did was ask for one for a 1967 Chevelle 396 w/th350 when I bought mine new. (alot easier than explaining a 409 to the counter person...) As far as I know, they are all the same except for the externally balanced ones of course.


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Supporting Member 5

Bob,we had a thread about flexplates awhile back.I used a 168 tooth also but mine fit tight so I had to lightly grind the flexplate with a die grinder or a half round file will work.


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I sent off an email to Fatsco Transmission to ask for their opinion.

We believe all the V8's from 55 to 61 take the same flywheel. We have them in stock for $177.00
Thank you,

Cool! There's one more piece where I don't have to buy the most expensive parts from some far away mail order business - but I did thank him politely and promise to keep them in mind for anything my Ironglide needs (at this point, god-only-knows what it'll need).

Last night I looked closely at what I need for shifting my 348/ironglide powered T Bucket. The shifter is from a 62 or 63 alloyglide in a Chevy II by way of the local swap meet - $20/perfect condition.

The ironglide has a shift arm that is about 3-1/2" long and swings about 80 degrees from the 8:30-oclock position (Park) to the 5:45-oclock position (Low). Total travel is about 3-3/4". The shifter has an arm about 4-1/2" radius and swings about 60 degrees. Total travel is about 3-1/4"

Right now I'm thinking of making some kind of bracket to attach to the tranny's shift arm that will shorten it's effective radius, which will shorten it's effective travel; and move the attachment point to a place where the shift rod won't go "over-center" at the Park position.

Anyone have any ideas that will save me the hassle? It looks like the governor cover is in the way of a straight link between shifter & trans - have to rig something anyway.
Bob: you didn't ask for one from a 1967 Chevelle 396 with a Turbo 350, they only put Powerglides (very few) and T400's. But a PG and T350 would be the same.

PS they never put a T350 behind a big block.


Fran Preve said:
Bob: you didn't ask for one from a 1967 Chevelle 396 with a Turbo 350, they only put Powerglides (very few) and T400's. But a PG and T350 would be the same.

PS they never put a T350 behind a big block.
Afraid your wrong there Fran. Check some suffix code listings for 1967 Chevelles and you'll see a bunch listing the TH350/396 combo. 1967 was the first year for the TH350 in the Chevelle and is why I asked for that year instead of 1966 which is the year of my car. :takethat


Turbohydro 350

Bob: How could this be? The Turbohydro 350 wasn't released until the fall of 1968 for the new '69 models. There were some test 350 hydros installed in '68 Impala lease cars so Chevrolet could keep track of them but none before then.


I was incorrect about the '68 Impalas 350 turbohydro lease cars. They were released to Chevrolet employees as company cars.

Chevrolet Service Bulletin to dealers. # 68-I-6 dated June 20, 1968

"A group of 1968 passenger cars will have an optional 3-speed automatic transmission which has not been previously used by Chevrolet. This group of vehicles will be initially assigned as Chevrolet Motor Division company cars and will be sold in the normal manner upon completion of company car service. This bulletin is intended to provide basic information should you encounter a vehicle with this transmission."


Fran, I have to eat some of my own words. :doh After looking closer, they must be referring to the 400 instead of the 350. All it says is "turbohydramatic". I knew there was a 3 speed for the first time in a Chevelle in '67 as I could even visualize the shift pattern on the console but I got a bit confused I guess. (not hard to do for me)

So the 400 came out before the 350??? :? Whats up with that? I did find out that this was only available with the 396.

Maybe when I asked for the flex plate, I may have said 396 with 3 speed auto??? That was a long time ago so I have no idea anymore. Whatever I asked for, it fit. :D


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Supporting Member 9
aren't T400 and T350 the same Flexplate (168 tooth)?
The TH400 torque converter uses a different bolt pattern than the TH350. Some flex plates are punched with both patterns, some are not.

I did not think the TH350 was used behind a big block either. I will check my books.



Turbo 400

I didn't realize the 400 trans was available with some small blacks. The turbo 400 was optional on the '67-'68 Impalas with the 327/275 and also the '70 Z/28s.

There was also a Turbohydro 375 in the 70s.