Author Topic: Engine/Transmission Swap  (Read 1841 times)

Offline Jeff

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Engine/Transmission Swap
« on: February 06, 2010, 09:14:55 PM »
I have a '74 C10, 2wd, step side, 6 cyl, 3 spd MT, heater only, no PS, no PB & no radio.  Cab & front clip have been restored.  My donor truck is an '86 GMC Sierra 1500 4x4, AT, PS, PB, AC (rock crawler/mudder truck) Allegedly, it has a 454 V-8 from a '70 Chevelle SS, a 700R4 AT, mated to an NP 205 twin-stick conversion, and a bunch of other expensive parts.....What I would like to do, is remove the current in-line 6 cyl eng, radiator, and manual 3 spd transmission from the '74 C10, and install my radiator, 454 engine, automatic transmission, floor shifter, complete dash & gauges from the '86 GMC.  *I'm wondering about the 700R4 tranny.  Since, I'm not going to use the transfer case, and the tail section will be shorter after I separate these two components, will a drive shaft (longer one will now be required) -slip yoke just slide over the tail shaft of the 700R4?
     In other words, I want to leave the '74 C10 as a 2 wheel drive truck, just a bigger engine with all the nice luxurious accessories,  and still utilize the automatic transmission that is actually shorter in length, and is intended for a 4x4 application?.  Sorry for the long post, English, grammar & punctuation is not my forte'.  Thanks in-advance for your info & comments. ;D

Offline Irish_Alley

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Re: Engine/Transmission Swap
« Reply #1 on: February 06, 2010, 09:31:16 PM »
so you want to make your 4x4 tran a 4x2 just by removing the t case, if i understood you right it wont work that simple you have to rip your trans apart to do that as far as i know.  and if you could do it yes you would need a new shaft
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Offline Jeff

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Re: Engine/Transmission Swap
« Reply #2 on: February 06, 2010, 09:43:59 PM »
 Thanks for your quick response!!; Do you think I could deliver this to a reputable transmission repair shop, and pay for this alteration?  Also, I'm wondering if my 14 bolt rear-end will swap into the '74 C10?  If it can, that will only leave me with a front axle, custom winch-bumper, and a transfer case to get rid of. 

Offline Blazin

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Re: Engine/Transmission Swap
« Reply #3 on: February 07, 2010, 01:03:46 AM »
The dash is not going to work its to far a year spread. The output shaft is different in the 4x4 trans. You need a 2 wheel drive output shaft, and a 2 wheel drive tail shaft housing. My opinion it would be less headache if you just found a 2 wheel drive trans, and had it rebuilt.
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Offline Captkaos

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Re: Engine/Transmission Swap
« Reply #4 on: February 08, 2010, 04:35:29 PM »
Or just buy a 2WD trans since the shop is going to have to pull everything apart to convert the output shaft that you don't have and if you are going to dismantle it I doubt they will put it back together like it came and warranty anything, I wouldn't.

The dash will work if you use the cluster with it, but you will have to change the wiring as the 74 has AMPS and the 86 has volts.

Offline Jeff

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Re: Engine/Transmission Swap
« Reply #5 on: February 09, 2010, 04:52:06 PM »
Well, I've got some good news (I think?).  I called a local transmission shop, the owner said he had the required output shaft.  He said if I brought the transmission & torque converter to his shop, he would retrofit it, rebuild it, and install it in my '74 C10 for $1500.00.  I forgot to ask about the warranty.  I priced a kit from PATC for around $932.00 (including the torque converter).  At any rate, I've got all the necessary equipment (TV cable, etc.) to implement it's installation to the 454/Edelbrock carb.
     I bought a "universal"/GM wiring harness.  I plan on completely gutting and removing my entire '86 dash, gauges, A/C-Htr controls, duct work, etc., and installing it in the '74.  I know it will be a pain-in-the-posterior, but the desire for A/C & nice gauges feeds my ambition and determination for success!.  As a matter of fact, I'm removing the old 6 cyl eng, 3 spd man trans, and old wiring.  The step side bed will be the last phase of this restoration/rebuild.  Thank you very much for the info regarding Amps vs Volts, just don't quite understand what message you're trying to convey.  Sorry, I veered-off the initial topic of my post, I really appreciate your help.  I will post photos, when I return back to my residence.  Currently, I'm in the metro Wash D.C. area (I'm sick of snow :P).