The Ford Barn - View Single Post - Max Speed of a Model A with 26% OD and HC Head

larrys40 · 04-22-2021, 08:34 PM

I’ve install a number of overdrives and have them in both my sedans
31 slant window std head currently with 26 Mitchell . I did 76 with it last fall on a trip. A could easy cruise is 55-62 in the highway.

My 30 tudor has a 5.5 head and a 3.54 rear end and a 23 percent Ryan overdrive . It is a wonderful mix and is a great highway cruiser. Top speed beat my town sedan. But only wrapped the speedo once .
It has been up pikes peak and many miles . 55-62 is still a great freeway speed as well.

I think the overdrive and 5.5 head is the best thing you can do to make them cruise a little easier and lower your engine rpm’s so it’s a little less strain on the engine and you. Yes you MUST have the brakes and front end in top notch condition .
My cars screech to a stop and handle superbly.... but that’s what I do. I also have never balanced Model A wheels and tires and have never had issues at higher speeds.
The reason for the overdrive and the head should be for drive ability and not for speed.
I’m not necessarily a fan of the synchro overdrive trans units although understand why some like them. With the correct ratios they are a pleasure to drive and help with those who have trouble double clutching for one reason or another.
We are blessed to have the options out there we have. The Model A community is truly a great thing.
Happy motoring!
Larry Shepard

04-22-2021, 08:34 PM	#21
larrys40 Senior Member Join Date: May 2010 Location: St Charles , Missouri Posts: 1,998	Re: Max Speed of a Model A with 26% OD and HC Head I’ve install a number of overdrives and have them in both my sedans 31 slant window std head currently with 26 Mitchell . I did 76 with it last fall on a trip. A could easy cruise is 55-62 in the highway. My 30 tudor has a 5.5 head and a 3.54 rear end and a 23 percent Ryan overdrive . It is a wonderful mix and is a great highway cruiser. Top speed beat my town sedan. But only wrapped the speedo once . It has been up pikes peak and many miles . 55-62 is still a great freeway speed as well. I think the overdrive and 5.5 head is the best thing you can do to make them cruise a little easier and lower your engine rpm’s so it’s a little less strain on the engine and you. Yes you MUST have the brakes and front end in top notch condition . My cars screech to a stop and handle superbly.... but that’s what I do. I also have never balanced Model A wheels and tires and have never had issues at higher speeds. The reason for the overdrive and the head should be for drive ability and not for speed. I’m not necessarily a fan of the synchro overdrive trans units although understand why some like them. With the correct ratios they are a pleasure to drive and help with those who have trouble double clutching for one reason or another. We are blessed to have the options out there we have. The Model A community is truly a great thing. Happy motoring! Larry Shepard Last edited by larrys40; 04-22-2021 at 08:41 PM.