Newbie mopar guy

Hi, my name is Brett and I live south Florida. I just purchased a 1939 Plymouth P7 coupe off eBay and have so far found this forum to be very helpful. My Plymouth is a bone stock, 201 ci flathead, 6 volts, 3-speed on the floor. The car drives better than I thought it would but I am looking to make a few changes to make in more drivable. I am not that knowledgeable about cars but I get help from my father, who is (his daily driver is a 57 Chevy pickup). Some of the changes I would like to make are to add an A/C (hot down here), turn signals, seat belts and front disc breaks. I was thinking I might replace my stock engine with a 230 ci and add some hop-up parts. However, after driving it a while the power is actually acceptable but what I don’t like is not having an overdrive and with it being geared so low it tops out to quickly. I’m doing OK on getting the parts mentioned above but I am struggling trying to find info on either an over-drive I can add or different transmission, like a 4 speed, that would be a simple swap without too much modification. I would like to be able to do 65-70 on the highway so if you have any advice on what type of transmission or O.D. that would work well and where I could get one I would appreciate it. I’m sure I will have many more questions and problems in the future so I am very happy to be here.

Regards

 

Let me be the first to welcome you to the HAMB! Very nice ride. I have a '37 Plymouth P4 coupe. It USED to be a bone stocker, although it didn't run when I got it. So, I pulled the dead inliner and bought a '53 Hemi to drop in it. It has been an ongoing project, but those are the best kind.

 

Welcome to the HAMB. Your overdrive problem may have a ready solution with fellow HAMBer pjplymouth aka Paul Curtis from Roseville Michigan.
pjplymouth@netscape.net
He is currently making adapters for the old MOPAR 6cyl. & 4cyl.engines so you can bolt a Borg Warner T5 five speed overdrive manual transmission to your bellhousing. I'm in the midst of doing the same swap to my '48 Dodge coupe. His prices are extremely good so send him an E-mail and talk to him, he's very knowledgeable and helpfull.
Vern.

 

Thanks for the info Vern. I e-mailed pjplymouth about getting a trans adapter so hopefully that will end my search. I have read only the T-5 from a S-10 is compatible because it has the shifter towards the front of the transmission and the mustang trans have them in the back. Is that right? Are there any changes I am going to have to make to the shaft and/or the cross member or its location? Thanks in advance.

Brett

 

Hi Brett: The Chevy S-10 is the one that you will have to use because of the shifter location. The other consideration is the speedometer drive. The pre 1993 S-10 trucks had a non-world class T5 trans with a mechanical drive speedo, the later ones were a world class T5 with an electronic speedo sender. If you are going to stay with the mechanical speedometer then you need to find an earlier trans or if you get a later one then you will have to change the tailshaft housing to one of the earlier style and swap the metal electronic speedo drive gear for a plastic mechanical drive gear. You will need the driven speedo gear and the small housing that holds the gear.
If you go on the internet and put in T5 transmissions on Goggle you will find a wealth of information. Also find an old transmission shop that has been around for decades usually an independant operator as opposed to a chain type shop and talk to the oldest mechanic in the shop and these guys are generally a gold mine of info.
The driveshaft will have to be modified or changed to fit the S-10.If you find a trany try to get the driveshaft with it so you have the right driveshaft yoke for the transmission. As far as the cross member goes I could'nt say for sure but ask Paul Curtis (pjplymouth) he would have abetter idea as he has a Plymouth of that era. If I can be of any further confussion to you give me a shout.
Vern.