Auto to Manual U-Joint

[MasonBraaps]

I have a 1988 c1500 reg cab short bed truck. Originally had a 700R4 in it. I have swapped in a HM290 5 speed.

Since the HM290 has a 32 spline output shaft and the 700R4 has a 27 spline, I need to change slip yokes on my driveshaft. I found a manual 32 spline slip yoke off of an aluminum driveshaft from a different truck. I wanted to put this yoke on the original steel shaft from my truck.

After reading the forum I saw that some guy said to get a MOOG 447 conversion U Joint. When I tried to press this into the yoke it snapped the ear off.

Now I need to get a new slip yoke, but I have no idea what size U Joint is meant for this combination. It seems like no one knows??

It seems like the Spicer 2-3-10831X slip yoke would work, so I understand I need a 1310 style for that end of the u joint, but what size do I need for the steel driveshaft end?

Any help is appreciated guys!

 

[Schurkey]

GM often uses their own sizing for U-joints.

If the yoke you're buying is advertised for a 1310 U-joint, I bet the shaft takes a 3R. Or find a yoke that accepts a 3R joint, and then you'd probably use a plain ol' ordinary 3R U-Joint.

Find the oldest parts-counter man in the building, ask him.

www.dennysdriveshaft.com/c974_universal_joints_by_size.html

Universal Joint size and dimensions specifications and part numbers 1000 series to 1880 series

Denny's Driveshafts stock a wide variety of universal joints in various sizes for all car, light truck and heavy truck applications. Choose from 1000 series to 1880 series from the industries best brands Dana Spicer, Neapco and AAM

www.dennysdriveshaft.com

 

[MasonBraaps]

Ok so after more looking around, I think I’m going to go with the Spicer 2-3-10831X slip yoke, and a MOOG 355 u joint, which is a conversion joint from 1330 (yoke side) and 3R (driveshaft side). I think this should work? Unless anyone sees an issue?

 

[Schurkey]

Did you measure the driveshaft? There's a chart in the Denny's link.