How hard is it?

[thirdstreettito]

How hard is it to swap a SM465 for a M22? 66 1/2t LWB 350. Driveshaft? Crossmember? Etc Etc

[Eagar1]

I am not sure the input shaft has the same number of teeth or even if the M22 will bolt up to that bell housing, and I don't know if any other trans that came in the truck had the same length or output shaft, so it will be interesting to hear from others what it will take.

My guess its a bear cause you will need to change bell housing, clutch, linkage, shifter, crossmember fab, special driveshaft, etc. so..... if you are going to use it as a truck keep the granny gear, if you are gonna just cruise it then its worth it to go with the M22 they are very strong and should handle a hopped up small block or even a mild Big Block.

[19GMC63]

you could probably use your bellhousing, but the M22 probably has a smaller bearing retainer than the SM465. You would have to have a ring machined in the bellhousing opening, or there may be a larger aftermarket bearing retainer for the M22... I don't know. Either way, this would allow to keep your stock linkage then you would swap the 10 spline clutch disc for a 26 spline one.
The SM465 uses a fixed yoke, M22 uses a 32 spline slip yoke, so that's something to remember.
The SM465 only uses the bellhousing mounts and not a rear one... the M22 probably does.

If you are going to go through this trouble, I would probably go ahead and find something with overdrive for cruisability.

[Jimmy S.]

I would try to find a new process made MY6 trans. Four speed.fourth being overdrive.

[thirdstreettito]

Thanks guys, I'll see if I can eventually put a M22 in.