[FC] '61 Rampy info

[James Davis]

The numbers you quote (38xxxxxx &37xxxxxx) are casting part 
numbers.  The 61 transmission assembly numbers are stamped on the 
data plate, the smooth surface below  the diff speedometer drive and 
the transmission fill plug.  BF 2-21 is the diff code for a open, 
manual, 3.55 differential with a manufacture date of February 
21.  The year is not specified so it could be for a 61-63.  The 61-63 
transmission input shaft is a 12 spline one with a total length of 
23&5/16 inches.  The seal portion of the shaft is 0.703 inches.  The 
65 shafts are same length but have 14 splines on the end and a seal 
diameter of 0.762 inches.  The part nunber for a 61-63 4-sp FC 
transmission is 3864460.
Please note there were two 61 Rampside four speed 
transmissions.   The early ones had a 4.26:1 first gear and the lates 
(probably what you have)  have the 3.65:1 1st gear.

The following in Craig Nicol take on the same subject (2004).

Hi Gary
re: 4 speed side cover transmission ID

If it has a drain plug (faces the rear by the diff) or a 12 spline input
shaft, it is a 61-3

No drain plug or 14 spline input shaft = 64-5

Look at the casting date on the left side just rear of the shifter, last
digit = year

64-5 better 2nd gear shifting and durability, closer ratios, higher torque
capacity.

Now for the fun part: there were 3 different first gear configurations

Put it in first gear and install an input shaft, mark the top of the input
shaft and output shaft at 12 o'clock. (from neutral, gentle CCW and push in).
Rotate the input shaft CW three turns and continue to 2 o'clock.  If 
the output
shaft mark has come up to exactly 12 o'clock, it's a 3.20:1 64-5 car.  If
not, continue CW to 7 o'clock. If the output shaft is at 12 now, it's a 3.65
first. If not continue CW, past 12 (four turns now) and on to 2 o'clock.  If
that's what it takes to get the output to the top then it's a 4.26:1 
early FC trans.

4.26 early 61 fc
3.65 = all early cars and late 61 through 65 fc (sort out by input shaft
spline count)
3.20 64-5 cars

If it is a 14 spline 3.65 trans, you might have a buyer, (me)!
Craig Nicol

Jim Davis


  At 12:49 PM 2/6/2007, wern3 at juno.com wrote:
>Guys
>I am rehabbing my transaxle for my 4 speed Rampy, and have some ID 
>#s cast into the casings:
>Tranny:-GM 6 over 3833193 over A244
>Diff:- BF2-21 over 3780270
>Are these correct for a 1961 Rampside?
>I removed the clutch / P.Plate /Flywheel to find a badly burned 
>early model pressure plate and 9" clutch disc which I have since 
>ordered replacements for.
>Is the driveshaft any different froma '65 car unit? I may have mixed 
>up the original one with a spare i have in my garage from a rebuild 
>on a '65 model 4 - speed>
>Thanks
>'61 Ramp in group red
>'65 Monza 'vert (for sale)
>Tim
>