Top loader 3 SPD or 4 SPD rug how to identity?

[Dinoeater]

I have heard that there is a RUG 3 SPD as well as the 4spd. I am looking at one tomorrow for my 72 Ranger. How do I tell the difference 3 or 4 SPD. And is there anything else I should know?
I have a 429 in the 72'. The trans I am looking at your is supposed to be a close ratio 4spd. I have a 300 ratio rear end.
Any insight is appreciated.

[ultraranger]

I'm not certain if a truck top loader is the same as one for a car. If it is, there are a few things on the outside that will quickly indentify a 4 speed from a 3 speed. A 3 speed will have an aluminum tail shaft housing, 9 top cover bolts and 2 shift lever studs sticking out the drivers side of the case. Speedometer cable will enter the drivers side of the tail housing.

A 4 speed will have a cast iron tail shaft housing, 10 top cover bolts and 3 shift lever studs sticking out the drivers side of the case. Speedometer cable will enter the passengers side of the tail housing.

Short of being able to crossreference the I.D. tag, the only way to know a wide ratio from a close ratio 4 speed would be to count the number of teeth of the 1st gear inside the case or, to remove the 4 bolts that holds the bearing retainer over the input shaft. If the transmission is a wide ratio it will have a groove machined into the circumference of the input shaft about the mid-point of the shaft. If it's a close ratio, there will be no groove machined into the shaft.

A small-block 4 speed will have a 1-1/16" diameter 10-spline input shaft. A big-block 4 speed will have a 1-3/8" diameter 10-spline input shaft.

"303" is in reference to the centerline distance (in inches --3.03") between the input shaft to the cluster gears in the top loader 3 speed, as opposed to the much weaker Dagenham 277 (2.77") transmission. The Dagenham was known as the, 'paper transmission' because it had a reputation for breaking fairly easily.
http://mustangtek.com/transmission/Transmissions.html

http://www.davidkeetoploaders.com/idchart2.htm

http://classicbroncos.com/tech/toploade ... sion-guide

[Dinoeater]

Thanks for the help. Much appreciated.

[tnlprt]

Ultraranger

You might want to change your statement about the big block and small block input size

The main difference between the small block and big block inputs is the length of the pilot that goes in the bushing in the back of the crank shaft

The big block pilot is shorter than the small block pilot

http://www.davidkeetoploaders.com/toploaderhistory.htm

[tnlprt]

toploader input.jpg

[ultraranger]

Ultraranger

You might want to change your statement about the big block and small block input size

The main difference between the small block and big block inputs is the length of the pilot that goes in the bushing in the back of the crank shaft

The big block pilot is shorter than the small block pilot

http://www.davidkeetoploaders.com/toploaderhistory.htm

I was just going off the top of my head in the best I could remember about the differences. I guess it just proves I'm human and don't know or can't remember every single detail.

[ultraranger]

I didn't think I had gone totally senile;

http://www.mustangmonthly.com/howto/mum ... to_14.html

[tnlprt]

You had it 95% right the only difference is a 390 came with the small diameter input shaft

Also some of the Fairlane and Galaxie speedo come in on the drivers side

Mustang and cougar came in on the Passenger side