Manual to Auto swap?

[mizozuman2]

Hey everyone.

Here in a week or so, I'll be purchasing a truck. It's an '84 C10 SWB with a 350/4 speed. I have seen a lot of Automatic to manual swaps, and have seen that you have to change the trans hump in them. But what do you have to do with a Manual to Auto trans swap?

Driveshaft, flexplate, converter, trans, yoke? It'd be a TH350, or a TH400.

Yes, I can drive a manual transmission. But I am wanting to have an auto.

Please don't tell me "Just find an auto transmission truck and buy it instead". This is what I'm wanting to do, because the truck is in actual good shape for the price he wants.

Thanks for any help and advice!

[bake74]

     You got the basics down, you will not have the stalk on the steering column for and automatic.  So just put a floor shifter in and you will be set.  Otherwise you will have to change out the steering column and run the rods for the auto tranny shifter.
     If it was me, I would go with the floor shifter, I like the looks of those.

[Gusgusa1]

I was think of this on my 84. Please update thread with build info. Hard to find info on this. Thanks.

[mizozuman2]

     You got the basics down, you will not have the stalk on the steering column for and automatic.  So just put a floor shifter in and you will be set.  Otherwise you will have to change out the steering column and run the rods for the auto tranny shifter.
     If it was me, I would go with the floor shifter, I like the looks of those.

So something like a B&M Ratchet Shifter? Or are there other ones? I like how the Ratchet Shifters work, but i don't know how big their truck series ones are (Height wise), and I don't care to reach 2 feet while driving to shift it. Though "Drive" is the trans shifting, correct?

[mizozuman2]

I was think of this on my 84. Please update thread with build info. Hard to find info on this. Thanks.

I'll try to keep it updated as much as possible!

[zieg85]

I did this swap on a 79 C10.  It was so easy for me cause I went from a 3 speed manual and I had a parts truck.  The only thing I had to do was get a flex plate for the 250 engine and the kick down cable bracket for the transmission.  I just bolted the 2 shift levers together and used one of the levers to shift the transmission.  The previous owner had converted it to a floor shift.  The 3 speed manual had a 2 piece drive shaft and the TH350 truck had a one piece so I used that.  The exhaust pipe hit the one piece drive shaft so a slight bend was needed to get it to clear.  I left the clutch pedal in it for the neutral safety switch.  The radiator needed changed because mine didn't have the trans cooler in it.  Made up some cooler lines and off she went.  This had to be about 15 years ago and I didn't have the money for a new clutch when it went out so this was the best option at the time.  It was a beater truck and the automatic actually made it nicer

[mizozuman2]

I did this swap on a 79 C10.  It was so easy for me cause I went from a 3 speed manual and I had a parts truck.  The only thing I had to do was get a flex plate for the 250 engine and the kick down cable bracket for the transmission.  I just bolted the 2 shift levers together and used one of the levers to shift the transmission.  The previous owner had converted it to a floor shift.  The 3 speed manual had a 2 piece drive shaft and the TH350 truck had a one piece so I used that.  The exhaust pipe hit the one piece drive shaft so a slight bend was needed to get it to clear.  I left the clutch pedal in it for the neutral safety switch.  The radiator needed changed because mine didn't have the trans cooler in it.  Made up some cooler lines and off she went.  This had to be about 15 years ago and I didn't have the money for a new clutch when it went out so this was the best option at the time.  It was a beater truck and the automatic actually made it nicer

So did you have to change the Transmission hump in the truck?

[zieg85]

No the only time you would have to change a transmission hump would be to go to a SM465 from an automatic.  The automatic is fine in any hump configuration.

[mizozuman2]

No the only time you would have to change a transmission hump would be to go to a SM465 from an automatic.  The automatic is fine in any hump configuration.

Oh tank goodness. That was a big worry of mine. I can't weld for nothing! Haha And I don't want to pay a shop for it either.

[zieg85]

With the extra room between the transmission and trans tunnel your down force will be less but probably won't notice it under 100...

[mizozuman2]

With the extra room between the transmission and trans tunnel your down force will be less but probably won't notice it under 100...

Good thing I don't need it to go faster than 75-80. LOL

[roundhouse]

Find a donor truck. Grab the parts you need

Might be able to swap in a tilt wheel while you're at it

What trans does yours have the SM 465. With granny first  ?

[mizozuman2]

Find a donor truck. Grab the parts you need

Might be able to swap in a tilt wheel while you're at it

What trans does yours have the SM 465. With granny first  ?

Yeah, it's an SM 465.

and there's no trucks for a good price down here to make a donor truck. the problem is finding a SWB for cheap with the parts needed. Everything here is either a $20K restored truck, or a $500 long bed. That's why I snatched up this deal as soon as I saw it.

Does anywhere sell driveshafts? and which auto trans would be best to go with? I'm wanting to get a 383 stroker to 450 horses or so.

[roundhouse]

You can't use parts from a LWB donor?

I wojldnt want the whole truck but is would work pit better If you can grab all the parts from the same donor truck

Don't know about the trans.  A good built TH should be fine and you may be able to use a 4L60
I doubt the Normal AOD is strong enough

We used to have a 30 passenger bus with a 454 and I think it was a L60 trans

[mizozuman2]

You can't use parts from a LWB donor?

I wojldnt want the whole truck but is would work pit better If you can grab all the parts from the same donor truck

Don't know about the trans.  A good built TH should be fine and you may be able to use a 4L60
I doubt the Normal AOD is strong enough

We used to have a 30 passenger bus with a 454 and I think it was a L60 trans

I have to have a different Driveshaft for the swap. the LWB wouldn't have the correct driveshaft if I remember right. everything else would be able to be swapped, but not the driveshaft. which is the thing I need the most. I know the guy the owns the junk yard here, and I'm sure he'd cut me a deal on an engine and trans. But he has no SWB autos.