3spd flathead behind 283- will it last?

Hello. I am in the process of building up a 48 Ford F-1. I have decided run '283hp' - (not numbers matching) 283 I got from a 57 chevy. I was going to adapt it to my stock but rebuilt 3 speed that was behind the flathead using a fenton bellhousing adapter. Out back I will be running a 9", 3.50 trac-lok with roughly some 6.70-15 bias plies (coker classics or something like that). Before I spent all my money on this setup I thought I would ask if anybody who has done a similar swap thinks this gearbox will last or if I should bite the bullet and put in something a little more substantial like a 4 speed (t-10/muncie) . Thanks, Eric

 

Better drive it like an old Granny, or have a supply of transmissions to swap out.

 

I cant speak for your current 3 speed trans, but i dont think you'll need a muncie or t10. You can go with a more available(read affordable) 4 speed saginaw, or even a 3 speed saginaw from 60's GMs. Unless you want that extra middle gear a 3 speed will work fine. 3 speeds were optional on the L79 350hp 327. Theres a bunch listed cheap in the classifieds.

 

i agree. since you are going with an open drive rear end , why mess with adapting to the ford tranny. get a tranny like spity suggested... it will be cheaper, easier and more reliable

i'm sure adapting the new transmission to your existing crossmember wouldn't be too hard

 

First time you hit second gear to hard, bye bye tranny.

 

I'm running one behind my bored out 265 Chevy in my Model A. I haven't been any serious distance in it yet or put it under heavy load, but seems to be fine so far driving it normaly..... I guess the answer lies in how you plan on driving your truck....

 

Cool truck, Eric. Make sure you check out the bonus built group, and welcome to the HAMB.

 

Unless it's a period piece which I doubt, just use a modern transmission. I put many a mile on a 36 trans behind a 283 with no troubles but it has it's limitations. No power shifting etc.

Period tires with a 4" tread will usually break loose with a 3.78/4.10 Ford rears. With 3.50 gears and larger tires the trans becomes the weakest link in the chain.

 

What people forget is WHAT CONDITION ARE the GEARS??? because as gears get worn out they get sloppy and significantly weaker because they touch on less of the teeth, this is remidied in most places by shimming gears closer togather, but that is not possable in a transmission

 

I don't quite understand why you would want to run the Ford 3 speed when you are going to run an open drive. I could see it if you had a torque tube. The 283 would be OK with the flathead tranny as long as you didn't abuse it. Back in the day we ran anything in front of the Ford tranny using the readily available adapters from a zillion companys selling them. You could dump an Olds in a early Ford in a weekend with aftermarket motor mounts and an adapter kit.

 

Got a stock '52 F1 In my opiniom the trans is the weakest link , mine will really not go over 65 without sounding like its going to gernade, picked up a T5 with Speedway's bellhousing, intending to run a 8" or 10 bolt in the rear.

 

If you don't try to speed shift the transmission they will work well. trouble comes not from the power but the surge when you drop the clutch too hard and the gears overstress,
Use the clutch easy, don't try to race the thing, (words normally ignored), and the flat head transmission will continue to provide service for years. In otherwords , don't shock the gears.

I did drop 3 transmissions in one month when I missed the shifts slightly!

traderjack

 

Just for correction purposes the 48 through 52 F-1 trucks were all open drive shaft and did not have a torque tube so you don't have to "adapt" it over to an open drive line. You would be much better off going with a later trans as opposed to keeping the stock 3 speed tranny. While the stock tranny is fine behind a flathead it isn't suited well behind an SBC as it would grenade under hard use.

 

ihad a 51 pickup, with a 302 ford, orignal trans 3 speed side loader, i broke it a cople of times, doing stupid things. if you drive it easy and don't beaton it it will work, good luck

 

If you did beat on A 39 box just once you would have a cool collection of broken gears. but hey so what, some of us like to learn the hard way. lol Jared

 

Just for even more correction purposes, Ford went to open drivelines in light pickups beginning in '42, not '48. My bone-stock '46 Ford PU had an open driveline.

A friend of mine had a 283 with an adapter to the original trans in his '40 Deluxe coupe. He drove it many miles all over the country with no problems. I drove his car, and it would scoot!

Here's some info from a fellow HAMBer who is one of THE authorities in things flathead:

http://www.vanpeltsales.com/FH_web/flathead_transID_3speed-gears.htm

 

"3spd flathead behind 283- will it last?"

NO!

 

I have the original unrebuilt trans in my '36 Tudor. 20,000 miles or so with no problem behind a 283. It's not a race car. It's a driver. Wayno

 

Thanks for all the good input. After thinking it over I am probably going to go with a saginaw 4 speed, that way I won't be sweating a gearbox blowout when I have to smoke a rice burner and/or need to cause a ruckus. Eric

 

Take a look at a S10 T5. It will bolt up in place of any GM 4sp. John