Question for tranny swap. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MazaM · 10-15-2005, 12:20 PM

Hi to everyone. I'm turning to the board for some needed advice. I currently have a '80 2WD with a 305/350 tranny with the reverse starting to go out. I've been keeping a eye in the local classifieds for a used 350 trans to swap out. I may have located a 350/700 setup out of an 85 for a good price but not sure if it would be a direct swap. If possible, I would like to use the old 350 engine as a core for a reman, then bolt the the 700 back onto it and place it into the '80. Would that be a relatively easy exchange or would some modifications be involved? If not, what trans should I be looking for?
Thanks in advance.

apstguy · 10-17-2005, 12:55 AM

You would have to shorten your driveshaft and most likely move your tranny cross-member back. Other than that it is pretty painless. Make sure the 700 is in good shape. Stock one tend to go at 145,000 miles.

86 GMG · 10-17-2005, 09:34 AM

it is an easy swap but the driveshaft and crossmember do have to be adjusted the only thing that i can remimber.

Jonboy · 10-17-2005, 11:44 AM

The only other things I can think of are to make sure the TV cable is hooked up and adjusted correctly, and you will want to make the lockup work as well. I used the painless wiring kit in my Blazer, but there are instructions on www.73-87.com as well, I believe.

*GoobersBlueBurban* · 10-17-2005, 09:01 PM

You might want to have a transmission shop go through the 700 and make sure everything is in good working order. I know you dont want to put it in, and then have to take it back out to have it rebuilt. I know that my 700 went out at about 170,000 on the dot.

10-15-2005, 12:20 PM	#1
MazaM Registered User Join Date: Jun 2005 Location: Corpus Christi, TX Posts: 11	Question for tranny swap. Hi to everyone. I'm turning to the board for some needed advice. I currently have a '80 2WD with a 305/350 tranny with the reverse starting to go out. I've been keeping a eye in the local classifieds for a used 350 trans to swap out. I may have located a 350/700 setup out of an 85 for a good price but not sure if it would be a direct swap. If possible, I would like to use the old 350 engine as a core for a reman, then bolt the the 700 back onto it and place it into the '80. Would that be a relatively easy exchange or would some modifications be involved? If not, what trans should I be looking for? Thanks in advance.

10-17-2005, 12:55 AM	#2
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	Re: Question for tranny swap. You would have to shorten your driveshaft and most likely move your tranny cross-member back. Other than that it is pretty painless. Make sure the 700 is in good shape. Stock one tend to go at 145,000 miles. __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

10-17-2005, 09:34 AM	#3
86 GMG Registered User Join Date: Apr 2005 Location: Tulsa Oklahoma Posts: 943	Re: Question for tranny swap. it is an easy swap but the driveshaft and crossmember do have to be adjusted the only thing that i can remimber. __________________ square body trucks an addiction or an investment either way they consume all my extra time and money

10-17-2005, 11:44 AM	#4
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Question for tranny swap. The only other things I can think of are to make sure the TV cable is hooked up and adjusted correctly, and you will want to make the lockup work as well. I used the painless wiring kit in my Blazer, but there are instructions on www.73-87.com as well, I believe. __________________ 1974 Jimmy- 5.3/4L80e/NP241

10-17-2005, 09:01 PM	#5
GoobersBlueBurban Account Suspended Join Date: Oct 2005 Location: Paris Texas Posts: 161	Re: Question for tranny swap. You might want to have a transmission shop go through the 700 and make sure everything is in good working order. I know you dont want to put it in, and then have to take it back out to have it rebuilt. I know that my 700 went out at about 170,000 on the dot.



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