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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: 77c15 on July 31, 2007, 08:14:21 pm

Title: 91 firebird donor
Post by: 77c15 on July 31, 2007, 08:14:21 pm

I just scored a 91 formula firebird that had an original 305 tpi but was replaced with a rebuilt 71 350 and the original 700-r4 trans. was rebuilt before the 71 motor was swapped in. I work with the guy at AutoZone who sold it to me, and got it for $200 and the top end TPI setup I had laying around so he could put it on his 76 Z28. I love getting a deal (steal)! I will be needing some guidance in this swap, as I have never attempted to swap a 700-r4 into one of these trucks. Thanks, in advance, for the help I will be receiving from all of our talented members!

Title: Re: 91 firebird donor
Post by: Captkaos on August 01, 2007, 03:58:30 pm

700R4 swap is fairly simple, you basically need to move the trans mount back and drill new holes and shorten the driveshaft.

Title: Re: 91 firebird donor
Post by: mikeith on August 02, 2007, 05:04:22 pm

you think this could be why my tranny truck threw the driveshaft... the guy that put it all together said that my stock driveshaft fit fine.... something about havin a long necked th350? and i dont even know if he modified the stock transmission crossmember.... what exactly has to be done to the crossmember so i can make sure its been done and how long should the driveshaft be from weld to weld!
(sorry dont mean to threadjack)

Title: Re: 91 firebird donor
Post by: Captkaos on August 02, 2007, 05:13:23 pm

if you are using a 9" tailshaft th350, it should be an easy swap.  You just have to move it back for the trans mount to connect.

Title: Re: 91 firebird donor
Post by: 87GMC1 on August 02, 2007, 08:26:13 pm

I INSTALED A 700R IN MY 79 I JUST USED THE DRIVE SHAFT FROM THE 87 DONOR TRUCK AND PUT A KIT TO LOCK UP THE CONVERTER.

Title: Re: 91 firebird donor
Post by: 77c15 on August 03, 2007, 11:15:09 am

I got the motor and tranny in the truck this morning after taking them out of the bird last nite. I bought a stock TH350 tranny mount and it bolted right up to the 700-r4 and the crossmember. I am having an issue with getting the tranny to slide over to line up the mount to the crossmember, though. Any ideas on how to get one to slide 3-4 inches towards the passenger side? Two more questions: How do I get the lockup connected using the connector from the bird? Also, does anyone know where I could get an adapter to go from the speed sensor on the 700r4 to the speedo cable?

Title: Re: 91 firebird donor
Post by: 77c15 on August 03, 2007, 11:29:42 am

Pix of the progress can be seen here:

http://www.cardomain.com/ride/788720/10