Engine swap for a 53 M38A1

[sniperthx]

Hey I was wondering what kind of engine i could use to replace the stock one in my 53 M38A1. I would like to be able to use the stock tranny and transfer case. I would prefer it to be as drop in as possible. I would also like it to be completely without any sort of computer or a mess of vacuum lines. What do you guys suggest?

 

[sniperthx]

Oh and i'm going to swap the axles and was wondering what ones you would suggest. Keep in mind that this is going to remain near stock as far as it goes. I just want a more powerful engine and a more modern brake system. It's going to be used basically as a hunting four wheeler so yeah.

 

[gijohn40]

what engine, tranny, transfer case, axle are in it now so we can tell you what would be "like stock"?

 

[spaggyroe]

GM 4.3 V-6

Swap the trans for a GM (auto or manual of your choice).
T-case could be used, but it may be cheaper / easier to use something like a GM NP205 to avoid having to buy an aftermarket t-case adapter.


That's probably what I'd do with it anyhow.

 

[Magerdgr]

GM 205 is a pretty big case for an 81" wheelbase. especially if you are adding a new trans since most everything out there is longer than a T-90.

If it were me I'd swap to a petronics solid state distributer, better plugs/wires/coil, and if you still need more, add a Warn/Saturn overdrive and run with it. If its just going to be a hunting rig, you can't really beat what the army designed it with. On top of that, its only going up in value, and if you swap it all out, your just gonna lose money in the long run. If its really a builder you are looking for, then you are better off starting with a CJ-7 or YJ because you'll be miles ahead by the time you swap everything out of your M. I run a '53 M38-A1 stock, including 24 volt electrics and have for about 11 years and I have yet to find anything that I can't go up that I have wanted to with a bit of decent driving. I've run 4+ trails in Moab with it open on both ends with no prob. Spaggyroe can attest to that. I'm not saying that I'm an amazing driver, just that folks have taken these old goats anywhere and everywhere for over 60 years in stock form, so you really need to ask what your really after. Anyway, sorry for the rant, just really belive in these old beasts, and hate to see them hacked up and lose the history forever. On the other hand, do what you want, it makes mine worth more....

 

[Magerdgr]

BTW, if you do decide to adulterate your M, keep me in mind for the drivetrain, always nice to have a spare.

 

[sniperthx]

I think the engine in mine has already been swapped before. It has a flat head six in it and i'm not sure that the m38a1 ever came with a six. It has the stock tranny and transfer case. which at the time im not sure what they are. It's a three speed with a twin stick t case. If I can keep the engine and tranny in it then i will. I wonder though if you could give me any tips concerning the brakes. They don't work. On my 56 pickup that i had, i had the same problem. And when i tried to pull the front end apart, I found that there is a giant nut holding it on. I justbought this m38a1 and am really wanting to keep it as original as possible, and with this thread i was mostly just seeing what my options were in case the engine in it needed to be replaced. Any help would be appreciated. Oh and as far as the brakes, Do you think it would be possible to run two master cylinders and make one for the front and one for the rear? In theory this would provide more braking force. I guess then again these things are light enough that they would just lock up. Just trying to make this thing nice. And can you suggest any way that may make it easier to tow? Like the fact that it likes to wander everywhere when i flat tow it behind my truck.

 

[spaggyroe]

Your brakes are 4 wheel drum, non power. They should work ok if you're prepared to flex a little leg muscle. Don't expect them to perform like a new car though, it just ain't gonna happen.

Check your wheel cylinders to ensure that they aren't leaking or stuck. If so, rebuild or replace. Obviously replace the shoes if worn. Flush the system.

If you perform an axle swap like you mentioned before, you could definitely gain some braking performance if you add disk brakes / larger shoes. I wouldn't suggest the dual master cylinder idea. There are plenty of choices out there for master cylinders that have larger bores (creates more pressure but also requires more peddle pressure). Your stock master cylinder should be located under the drivers side floor, which may make it harder to perform a swap. That is if you keep the master cylinder in the stock location. I don't know what your options are for moving it to the firewall.

 

[Magerdgr]

Spaggyroe is right on your brakes, they are an easy rebuild and should work fine when they are all in working order, especially if you are planning on running stockish size wheels. Your original engine should be a 134F inline 4, I know what jeep you have now, I saw it for sale. You should also have a T90 trans and a T18 transfer. Your axles are a Dana 27 up front, Dana 44 rear. It should flat tow great once you work out tire/brake issues, I've flat towed mine across the country twice now and they do wonderful. Also check out your tie rod/bell crank/drag link set up and make sure that they are all tight. Your M is really a rare one in that it is a true first year production model. only the first 9 or 10 months of production had the seamed front fenders, 8 thumbscrew battery box, and hinged grill with no radiator supports and those are getting REALLY hard to find. Lots of times you see jeeps labeled as '52-'53 M38A1's only to find out that they are later models that have early data plates on them.
Check out http://www.m38a1.com/ for some great info and to tell how to find out your delivery date a little better since you are missing the dash data plates. Also check out www.willysmjeeps.com for more good info on it.
I live in Eagle Mountain, and drive my A1 through Lehi pretty much every day so if you need any help I'd be happy to stop by. I have a pretty intimate knowledge of these things and love to play with them.
Thanks

 

[sniperthx]

If you wanted to stop by and look you can give me a call. I believe i pm'd you my number and i'm home on sunday. If you could take a look. Oh and by the way, there's a f head six in it. I can't get the darn thing off the trailer right now. But yeah if you could look at it that would be great. Oh and if you could drive yours here I'd love to see what they look like after some work.

 

[Magerdgr]

I'd love to stop by and check it out, maybe I can help ya get it off the trailer too. If I remember right it had a flat head six didn't it? That would be an L-head, and I think that its out of an early wagon. I didn't get your message til today, but I'll give ya a call.