auto to manual swap

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Last year around christmas my brother and I did the auto to manual swap in my 91' LBRC. We removed the trans, crossmember, driveshaft and pedals from the donor truck. I didn't think about the steering column while destroying the dash to get the pedals out. Too late but it didn't matter the swap was done. I removed my turbo 400 and after buying brand new clutch, pressure plate, flywheel, throwout bearing, and the slave cylinder complete and some trans fluid the swap started. My truck is carb'd and don't have an ECM in there. The master cylinder was installed after drilling the 3 holes out that are dimpled in the firewall. The hole for the shifter is in the correct location as it was a raised piece from the factory. Cut it out and the shifter was located in the correct position on the floor. The donor crossmember was roached so we used the one that was already in the truck. I used the donor driveshaft and a new universal joint. Truck drives like a champ and with the torque of the mild SBC and the 3:42 rear gear it just pulls and keeps pulling. I later crawled under the truck and cut the auto plug off the speedo wires and spliced in the pigtail from the manual trans. Due to the donor truck also having a 3:42 rear gear it's dead on per the GPS speed app I have on my fone. I am however having trouble getting the back up lights wired correctly. Other than that it was pretty straight foward.
 
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no that pcm won't work, don't waste your time trying to use another truck's PCM to use, just get yours tuned for the correct trans/engine/VIN/etc...

I swapped my 4L60e for a T56, yours would be similar with the 5 speed. probably a few small differences. this is my 4L60e to T56 writeup if it helps you:
http://www.gmtruckcentral.com/articles/t56.html

I read your writeup on the T56 install. I did the NV3500. What wires did you connect to what to get the reverse lights to work? Right now I have the blue to blue, light green to light green. Do I need to have the black connected to a ground on the body somewhere? What about the orange with black stripe? Thanks
 

df2x4

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I read your writeup on the T56 install. I did the NV3500. What wires did you connect to what to get the reverse lights to work? Right now I have the blue to blue, light green to light green. Do I need to have the black connected to a ground on the body somewhere? What about the orange with black stripe? Thanks

He hasn't logged in here since 2014. Sorry I'm no help, just wanted to let you know so you weren't expecting a response from him. Hopefully someone else here has some info for you.
 
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Before you strip the donor look for the wiring for the reverse lights. There should be a green, lt blue, black and orange with a black stripe wires together under there. Also just the pedal and steering column is all you need. I messed up when I did the pedal removal cause I beat the **** out of the dash and steering column to get the pedal out. Afterwards I realized I could have used the column. Everything else is there. The dimples for the slave cylinder are on the fire wall just drill them out. I also bought all brand new clutch, FW, pressure plate, throw out bearing and the hydraulic system as it came together and bled already. Just install it and go. Also cut the wiring on the donor as far as possible from the plugs on the transmission. The splice them in to the wiring on the patient truck. The wiring for the speedo will work I will let you know later when I get home from work what two speedo wires need to be connected to work.
 

Shtbox69

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I stripped ABSOLUTELY EVERYTHING out of the '90. Been looking under dash of my 94 auto, and I did see the firewall dimples, but nothing for the rear of the clutch pedal bracket? Anyone else? If I drill the two holes, can I gain access to the topside of it to nut/bolt?
 

SStewart1

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I stripped ABSOLUTELY EVERYTHING out of the '90. Been looking under dash of my 94 auto, and I did see the firewall dimples, but nothing for the rear of the clutch pedal bracket? Anyone else? If I drill the two holes, can I gain access to the topside of it to nut/bolt?
I’m doing the exact same swap. 90 into a 94. Iv got some pictures of the clutch pedal mounted and everything. I need to know what wires to splice for the different brake light switch and reverse lights and neutral safety switch. You’ll have to make upper hangers for the closest edge of the pedal.
 

Shtbox69

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Hope it helps

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Thx for the info. I decided to go with a carbed SBC in mine. I bought the right ecm for the swap if you are interested in it? Bought used from ebay for a 94 2wd 305/5spd. I won’t be using it.
 
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