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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 83HighSierra on July 15, 2007, 06:44:40 pm

Title: Which Transmission???
Post by: 83HighSierra on July 15, 2007, 06:44:40 pm
Im trying to figure out what kinda transmission i got. Ive had one guy say i had a 700r4 but to me it looks like a th350. Can yall tell which one it is?

(http://i46.photobucket.com/albums/f105/C-dog01/DSC00562.jpg)

(http://i46.photobucket.com/albums/f105/C-dog01/DSC00555.jpg)
Title: Re: Which Transmission???
Post by: dumbucket1 on July 15, 2007, 07:08:02 pm
the long tailshaft and the vacuum modulator give it away as a th350 but I'm pretty sure that truck was built with a 700r4 when it was new based on the year of the truck.
Title: Re: Which Transmission???
Post by: 83HighSierra on July 15, 2007, 07:45:34 pm
Ya thats what i was thinkin i just wanted to make sure though. Do you know how to tell the difference between a 305 and a 350 because ive had different people tell me different things about the engine too.
heres a pic of it

(http://i46.photobucket.com/albums/f105/C-dog01/DSC00540-1.jpg)
Title: Re: Which Transmission???
Post by: dumbucket1 on July 15, 2007, 08:51:46 pm
externally a 305 and 350 are identical. You pretty well need to located the casting numbers on the block and find a website that decodes them. If the engine is original there should be a letter in the vin that will tell you which engine it is.
Title: Re: Which Transmission???
Post by: Captkaos on July 15, 2007, 09:13:45 pm
All 1/2T 2wd pickups from 1981 - 1986 only came with a 305, so that will eliminate a factory 350 on those.  California excluded.
Title: Re: Which Transmission???
Post by: 83HighSierra on July 16, 2007, 03:13:06 pm
so i have a th350 and my gauges are off, is there a article that tells how to fix it, would it be the same as changing the gears in a 700r4?
Title: Re: Which Transmission???
Post by: Captkaos on July 16, 2007, 04:33:41 pm
yes, it is virtually the same as a 700R4.
Title: Re: Which Transmission???
Post by: 1976Scottsdale on July 16, 2007, 06:47:44 pm
350 engines usually have a harmonic balancer that is 8" in diameter.  a 305 will be between 6 and 7" in diameter.  That is the thing behind the pulley at the bottom of the engine.