3 on the tree to sm465 conversion questions

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Jamesz

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Hey guys! I just bought my first c10 recently with no engine or transmission. I would like to put in a 350 with the sm465 but I don't know what parts I need to figure out fitment of the 4 speed on a 3 speed crossmember. I already have the transmission, clutch, flywheel, bellhousing, shifter handle, manual steering column, and a two-piece driveshaft that might fit it. The truck used to have the 250 inline 4 with a 3 on the tree so it has the pedal and some of the linkage. Has anyone done the swap and if so do y'all have any insights on what I should do to prepare for it?
 
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I believe that most of your manual stuff/linkage/hardware will work. I'd upgrade to a "12 clutch & also do a column swap to complete the changeover.

HS
 
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You may need a 2wd "high hump" bolt-in trans tunnel. Your 3/tree cab should have the low hump trans tunnel that was also used with automatics.

You can use the same crossmember, but it may get used with another set of holes in the frame.
 
AuroraGirl

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Jamesz said:
Hey guys! I just bought my first c10 recently with no engine or transmission. I would like to put in a 350 with the sm465 but I don't know what parts I need to figure out fitment of the 4 speed on a 3 speed crossmember. I already have the transmission, clutch, flywheel, bellhousing, shifter handle, manual steering column, and a two-piece driveshaft that might fit it. The truck used to have the 250 inline 4 with a 3 on the tree so it has the pedal and some of the linkage. Has anyone done the swap and if so do y'all have any insights on what I should do to prepare for it?
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This is a k25 so its 3/4 ton , but the crossmemeber and trans is a sm465. I dont know how the sm465 2wd mounts, but if it uses the two pads setup then its likely like this.. but ifi uses a single mount in center, then
 
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2wd 465 uses the single mount, like all the other 2wd's. There's two basic GM styles... one has two bolts for the crossmember, while the other just uses one. The common aftermarket urethane mounts, like Energy Suspension are designed to replace both styles.
 
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Why four when you can have five?
 
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SquareRoot said:
Why four when you can have five?
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I would definitely have loved to get a five speed but the transmission I got was a really good deal, so I had to go with it this time. But if I keep this truck for a long time I will most definitely be upgrading to a 5 or 6 speed.
 
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Jamesz said:
I would definitely have loved to get a five speed but the transmission I got was a really good deal, so I had to go with it this time. But if I keep this truck for a long time I will most definitely be upgrading to a 5 or 6 speed.
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6. Tremec
 
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After 5 you may as well just run a CVT lol.
 
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bucket said:
You may need a 2wd "high hump" bolt-in trans tunnel. Your 3/tree cab should have the low hump trans tunnel that was also used with automatics.

You can use the same crossmember, but it may get used with another set of holes in the frame.
Click to expand...
Okay cool! so I was just going to cut a small hole the size of the shifter to begin with but now I see what you are saying about the top of the transmission needing that extra clearance. I'll try and get one of those ordered. I was going to try and put the engine and transmission in this weekend, but I think for the time being just drop the engine in and put the transmission in later.
 
AuroraGirl

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SquareRoot said:
After 5 you may as well just run a CVT lol.
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its 5 with a granny low

so my bad I Thought it was 6 speed, But isnt the nv trans only 4 with a granny low?

Although they do sell more speeds, but the only difference is 1st becomes a normal range and 6th is a 2nd OD
 
AuroraGirl

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Jamesz said:
Okay cool! so I was just going to cut a small hole the size of the shifter to begin with but now I see what you are saying about the top of the transmission needing that extra clearance. I'll try and get one of those ordered. I was going to try and put the engine and transmission in this weekend, but I think for the time being just drop the engine in and put the transmission in later.
Click to expand...
your cab might not have a coveer which can be removed without cutting

So if you get a cover, you can cut it with that as a template
 
bucket

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AuroraGirl said:
your cab might not have a coveer which can be removed without cutting

So if you get a cover, you can cut it with that as a template
Click to expand...

Correct. Cut the opening so that there is still a 3/4" to 1" flange to attach the new trans hump. You can simply use self tappers, or drill larger holes in the base flange and use threaded j-clips, or install nutserts in the base flange for bolts to thread into. Having the removable cover is super handy too.
 
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