The Ford Barn

Grayble 123 · 05-26-2025, 02:02 PM

I’ve just had my C4 rebuilt for my stock flat head. Can anyone recommend the proper torque converter?

Ronnieroadster · 05-26-2025, 06:47 PM

The correct answer should be available from the company that provides you the conversion to put a C-4 behind your flathead.
Ronnieroadster

69a · 05-27-2025, 02:03 AM

You just need a regular torque converter but you have to match it to your flex plate/bellhousing (157 or 164 teeth on the ring gear) I think you may have to grind some off the engine block to clear the stater if you use the 157T.
Your adapter kit should come with a bellhousing adapter and either a 164 or 157 flex plate with a flathead center.
There is a difference in the spacing of the mounting studs on each flex plate. Also you have to match the spline on the front of the transmission (24 or 26) ? I'm not sure of the number, but you will have to count what you have.

Grayble 123 · 05-27-2025, 04:08 AM

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As far as getting the correct converter from my adapter provider Speedway sent me a converter that was a stall converter that was too high. The associate said it was the only one that would fit my 157 flex plate. I’ve have seen during my investigation for this issue Flatomatic may have reopened.

05-26-2025, 02:02 PM	#1
Grayble 123 Junior Member Join Date: Oct 2023 Location: Maryville,Tn Posts: 26	1951 c4 swap I’ve just had my C4 rebuilt for my stock flat head. Can anyone recommend the proper torque converter?

05-26-2025, 06:47 PM	#2
Ronnieroadster Senior Member Join Date: Dec 2010 Location: East Coast in CT Posts: 1,697	Re: 1951 c4 swap The correct answer should be available from the company that provides you the conversion to put a C-4 behind your flathead. Ronnieroadster __________________ I use the F word a lot no not that word these words Flathead, Focus and Finish "Life Member of the Bonneville 200 MPH Club using a Ford Flathead block First Ford Flathead bodied roadster to run 200 MPH Record July 13, 2018 LTA timing association 200.921 First Ford flathead roadster to run 200 MPH at Bonneville Salt Flats setting the record August 7th 2021 at 205.744 MPH reset the record in 2024 to 211.830 running to mile four. Top speed 2024 mile five 220.672 exit speed 221.587

05-27-2025, 02:03 AM	#3
69a Senior Member Join Date: Aug 2020 Posts: 262	Re: 1951 c4 swap You just need a regular torque converter but you have to match it to your flex plate/bellhousing (157 or 164 teeth on the ring gear) I think you may have to grind some off the engine block to clear the stater if you use the 157T. Your adapter kit should come with a bellhousing adapter and either a 164 or 157 flex plate with a flathead center. There is a difference in the spacing of the mounting studs on each flex plate. Also you have to match the spline on the front of the transmission (24 or 26) ? I'm not sure of the number, but you will have to count what you have. Last edited by 69a; 05-27-2025 at 03:01 AM.

05-27-2025, 04:08 AM	#4
Grayble 123 Junior Member Join Date: Oct 2023 Location: Maryville,Tn Posts: 26	Re: 1951 c4 swap Sponsored Links (Register now to hide all advertisements) As far as getting the correct converter from my adapter provider Speedway sent me a converter that was a stall converter that was too high. The associate said it was the only one that would fit my 157 flex plate. I’ve have seen during my investigation for this issue Flatomatic may have reopened.