I have a 1968 chevy truck. Custom 20. I need to know what type of Trany is in it. It looks like a Gm 17" spline, 10" ring....Help me some one please

Welcometo the board from Texas

Welcome aboard MOJO! The SM 420 was last used in 67's. Good chance that you have a SM 465. Here is some info.

This transmission is 12 " long and features a cast iron top cover that is retained by eight bolts. The SM465 case is of cast iron. The case itself is generously ribbed both vertically and horizontally. The SM465 (also referred to as the CH-465) has a 1-1/8" diameter, ten spline input shaft that has a stick-out of 6-1/2" from the front face of the transmission. The pilot tip of the transmission measures .588". The front bearing retainer flange measures an unusually large 5-1/8" in diameter and the bearing retainer tube is 1-3/8" in diameter. The front bolt pattern is the consistent GM Muncie / Saginaw four-bolt pattern as found on GM bellhousings and transmissions from the 1940's through the 1990's.

Specifications of the SM-465 Gear Box

The SM465 is a top loaded, top shifting truck style transmission. The 465 enjoys a very low compound gear at 6.55:1 and as such it is a popular choice for those wanting a very low crawling gear. The SM465 features power-take-off (PTO) ports on the passenger and driver sides of the case.
The shifting pattern for the 465 is in the standard "H" pattern with reverse gear being to the right side, and down. Later versions featured a fourth-gear switch for activating the cruising (lean) mode of GM Engine Control Modules. The last two years of the SM465's production saw it with an aluminum top cover.

A few of us Western WA members are going to the Monroe swapmeet tomorrow, can you join us? here is the link for info.

http://67-72chevytrucks.com/vboard/showthread.php?t=198188

Welcometo the board from Texas
Thank you
Do you have any info on where I can find out anout the trany?

Welcome from Spokane, WA

Welcome to the board from South Mississippi! Post your question on the Engine and Drivetrain board and you'll probably get more responses.;)

Welcome to the site! We need more folks from WA!

Welcome to the site.

Welcome from maine

:welcome2: From West TN :hi2:

Thank you all! Now I need to know about the rear end

Welcome aboard MOJO! The SM 420 was last used in 67's. Good chance that you have a SM 465. Here is some info.

This transmission is 12 " long and features a cast iron top cover that is retained by eight bolts. The SM465 case is of cast iron. The case itself is generously ribbed both vertically and horizontally. The SM465 (also referred to as the CH-465) has a 1-1/8" diameter, ten spline input shaft that has a stick-out of 6-1/2" from the front face of the transmission. The pilot tip of the transmission measures .588". The front bearing retainer flange measures an unusually large 5-1/8" in diameter and the bearing retainer tube is 1-3/8" in diameter. The front bolt pattern is the consistent GM Muncie / Saginaw four-bolt pattern as found on GM bellhousings and transmissions from the 1940's through the 1990's.

Specifications of the SM-465 Gear Box

The SM465 is a top loaded, top shifting truck style transmission. The 465 enjoys a very low compound gear at 6.55:1 and as such it is a popular choice for those wanting a very low crawling gear. The SM465 features power-take-off (PTO) ports on the passenger and driver sides of the case.
The shifting pattern for the 465 is in the standard "H" pattern with reverse gear being to the right side, and down. Later versions featured a fourth-gear switch for activating the cruising (lean) mode of GM Engine Control Modules. The last two years of the SM465's production saw it with an aluminum top cover.

A few of us Western WA members are going to the Monroe swapmeet tomorrow, can you join us? here is the link for info.

http://67-72chevytrucks.com/vboard/showthread.php?t=198188
Thank you! What do you know about the rear end? I guess I kind of asked that but it was all jumbeled up. 17" spline....10" ring.....what did chevy put in them? any ideas?

Since it's a Chevy 99% chance you have a Eaton rear. Big round smooth diff cover? Time to take some pics and read through the older postings of the board. Everything you want to know has been asked before... even by me.

Welcome to the forum Mojo...:)

Welcome from Spokane!:metal:

:welcome2: To The Boards MOJO From Brian Of Olds...Alberta, Canada.