SM465 Side Cover/ Top Cover?

[NemesissParadise]

I need a new transmission in my 85 k20. It currently has an auto, Since I Prefer a manual it seems like a perfect time to swap. Looking for a Transmission I went on Car-Part.com. It asked me if I needed a MT, (4 speed), side cover or 4x4 top cover. I didn't know what the difference was so I called a local junk yard to see if they had a transmission. They asked the same question. When I asked what the difference was the response was a bunch of errrrs, n umms. So being that I am swapping transmissions what's the difference and is one better to use or is it just thing GM did to make things more complicated when finding parts?

One other question. I am sure many threads have covered this so any good threads have answers to best places to get the misc. parts I'll need(aka pedal, clutch etc)?

 

[Charlie]

 

[CSFJ]

I would almost bet that they're referring to the shift cover. If that's the case, the sm465 (4spd, extra low creeper gear, 1:1 final drive ratio) is a top cover. The other factory option, would be the np833 (4spd, 4th gear being an overdrive with a .70ish:1 final drive ratio) is a side cover. The sm465 is a fairly common trans, and is generally considered to be quite bulletproof. The np833 is far less common, and while it doesn't carry the same reputation for robustness as the other, it is still a stout trans. If you viist our transmission sub-forums, there are more in-depth threads about each.

 

[CSFJ]

Locating the rest of the parts to do this swap will probably be an exercise in patience, as no one does new repops of the pedal assemblies and such. Bushings and small wear items are usually available, but you'll need to find used original parts to start with. If you can find a manual trans parts truck somewhere, that would be the closest you'll get to one stop shopping.

 

[NemesissParadise]

Thank you everyone. Are the pedals the same for the square body run or did they change when it became a hydraulic clutch?

 

[CSFJ]

I do not know. The assemblies will all bolt in, but I don't know what, if anything changed on the pedals themselves. @bucket may know, but I've never had a linkage set next to a hydro set to be able to answer with any certainty.