Hey, I'm new here so please be nice.I'm in the very early stages of putting a 390 in a 62 unibody.I have been reading some threads on trannys, and wondering if a overdrive toploader style tranny will hold up to a fe motor.Also any input on a 390 in a unibody. THANKS

 

Search around look for srod. Most will say not strong enough, however I have one sitting on the floor of my garage just waiting to gather the rest of the parts for the swap. My small understanding is the first 2 gears are the same as a normal toploader. The 3/4 are swaped linkage-wise to get the OD. The older designs had a weak OD system running on bearings that were prone to going out. I have an 87 here. not even sure If I can the speedo to work (wrong side)

My advice swap it especially if you have a manual. Let me know how it holds up.

bob

 

If you just cruise it, it will survive. High horsepower powershifts will end it quickly!

 

Depends which tranny. If it's the iron case overdrive with an external shifter it will probably last OK if you don't abuse it badly. The main thing is the ratios suck as bad as a normal truck 4 speed. They aren't like a car 4 speed.

They have a 3.29 1st, then a big drop to 2nd (1.79 i think) and a horrible drop to the 1:1 "3rd" which is actually 4th but the shift lever is turned upside down. The overdrive which is in third position is .80:1 , the ratio drops are worse than a normal 3 speed.

 

I'd be curious to hear how that RUG toploader works behind an FE. With a rear gear like a 3.25 it might be an ok option. You'd have to tune the engine to have a wide torque band with good low-end torque to deal with the wide ratios.

 

If you want to go with a real overdrive, why not go with the T-85? This was the last o/d used in an FE engine, 1958-65 Ford full sized passenger cars and 1965-67 F100's with the 352.

 

Since this transmission is destined for a 62, the OP is probably thinking floor shift. I saw a RUG toploader with a top mounted shifter on ebay. The reason I like this option is because it will bolt up to a stock type bellhousing and use the stock floorboard. It will look like a stock transmission but give the overdrive option.

 

I have the exact set up. It's a '62 Unibody with a tri-powered FE connected to an SROD. I've put 30K miles on it and so far so good. I use it for basic transportation. The gear ratio does suck if your racing....especially 2nd - to - 3rd, but the overdrive makes it worth it. My rear gear is a 3.25 and I can get 16mpg on the highway.

 

A 390 will have no problem with the wide gear ratio spreads. I had a 67 Stang that came with a 390 and a T&C Toploader 3 speed plus a 3.00 rear. This car ran low 14's with this setup. Raced a built 350 Chevy once in a 69 Camaro that was backed with a 4 speed and 4.11's. The 390 slowly pulled away from the Chevy thru the 1/4 mile. Then repeated the act after the Chevy guy couldn't figure out what happened. He would run thru 1st and 2nd before I shifted out of 1st.

 

I installed an SROD (Single Rail OverDrive) behind the 360 2bbl in my '68 F100, replacing the 'RAT' series 3-speed toploader manual. I cut a hole in the floor for the shifter, which comes up just ahead of the front of the seat. I was looking for a lower 1st gear ratio for easier starting when pulling a trailer, AND an overdrive to get the revs down during highway driving. The SROD does both. The SROD bolted up in place of the 3-speed, and uses the same transmission mount. NOTE: There are at least 2 versions of the SROD, the external difference being in the length of the input shaft where it engages the pilot bushing, the length of the clutch splines, and the length of the tube that carries the clutch release bearing. The driveshaft coupling uses a slip-yoke. The SROD tail housing is longer than the 3-speed, so I had to go to a shorter front driveshaft. (I have a 2-piece shaft w/center bearing). My diff ratio is 3.50 or 3.55 if I remember correctly. This is a 'utility' setup, NOT a 'performance' setup, and I drive it gently (but the ol' truck feels relaxed cruising at 75-80 mph.) Ratios are very wide. Everything is working great except the speedometer gears didn't match up, so no speedo. The SROD is out of a Mustang, about 1980 vintage. I understand that the 'TOD' (Top OverDrive) installed in some of the pickups has larger main ball bearings.

I hope this helps!
----------------
Jim Jelinski '68 F100 360--'60 Triumph TR3A--'73 Triumph TR6--'59 Cessna 172

 

i also have an srod hooked to a 352 w/ 3.25 rear. when i frist put it in i had a 3.00 rear.it wasn't to bad starting off but the 3.25 are much better was thinking of going to 3.50s.if i remember right use one from a truck cause the car version has smaller bearings.