did all (non manual) 91 silverados come with 4speed (overdrive ) trans missions ?

 

If we're talking 1/2 ton, yep. It would have been the 700r4. They did produce big block 3/4 ton trucks with the 4L80E, first year for those though.

I believe they were making the SS454 truck back then, which would have come with a TH400 3 speed.

That's off the top of my head, and I'm an old guy! Did you check it out on Wikipedia?

g

 

without jacking the thread, I just picked up a 1990 GMC 2wd 5.7, the overdrive is out of the trans, I lucked out and found an older 78-87 style 2wd 350, the only thing I have to go off of is the '90 had 1,2, & OD.. and the older truck had 1,2 & D... this is just going off the dash indicator, have not crawled under and looked or anything, he said it would fit and it worked so I said sold, now what have I bought? would this most likely be a th-350/400 or is it just a 700R4 without OD? newbie so just asking I looked in wiki, but figured I'd check here

 

Turbo 350 or Turbo 400. Look at the trans pan and you will know immediately.

 

91 454 SS trucks had the new 4L80's too. 90 was the only year for 3 speed trans in the SS. As far as I can remember, all the Chevy's had overdrive in 91.

 

if you're ever in doubt about an older chevy tranny check this link...

Chevrolet Chevy Transmission Identification and Decoding

 

thanks for the link, ill check it out this week, i bought it without crawling under the truck... guess i'll find out soon