1990 k2500 vac line

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

PlayingWithTBI

2022 Truck of the Year
Supporting Member
Joined
Jan 3, 2019
Messages
9,550
Reaction score
14,672
Location
Tonopah, AZ
I thought GM didn't change their designations until mid to late 90, like the 700R4 to the 4L60?
 

PlayingWithTBI

2022 Truck of the Year
Supporting Member
Joined
Jan 3, 2019
Messages
9,550
Reaction score
14,672
Location
Tonopah, AZ
Thanks, I'm not trying to stir the pot any :anitoof: just trying to get the evolution of these transmissions straight in my head. Being as I have a "built" 700R4, I was kinda hoping there was a 4L80 non-E I could use but, it doesn't look that way, huh?
 

evilunclegrimace

Does not always play well with others
Joined
Sep 18, 2017
Messages
2,288
Reaction score
2,332
Location
pennsylvaina
Thanks, I'm not trying to stir the pot any :anitoof: just trying to get the evolution of these transmissions straight in my head. Being as I have a "built" 700R4, I was kinda hoping there was a 4L80 non-E I could use but, it doesn't look that way, huh?

I understand Peter, I left the "E" out of my post so it was a bit misleading. IF I knew of a 4L80 that was not electric I would buy all of them that I could find.:waytogo:
 

someotherguy

I'm Awesome
Joined
Sep 28, 2013
Messages
9,795
Reaction score
14,156
Location
Houston TX
Not true , My 1988 K3500 came with a THM 400 RPO code M 40

The naming convention changed around 1987, hence my ;) and :D about saying TH400's never came in a GMT400. I know they did. They were named 3L80's though. Just because an old RPO list refers to it as a TH400 doesn't mean that's what GM called 'em at the time the truck was built. :)

I've owned one or two GMT400's so trust me when I make a statement you may not agree with, and it's followed by a wink or grin emoji, I *just might be joking instead of wrong*

Richard
 

evilunclegrimace

Does not always play well with others
Joined
Sep 18, 2017
Messages
2,288
Reaction score
2,332
Location
pennsylvaina
The naming convention changed around 1987, hence my ;) and :D about saying TH400's never came in a GMT400. I know they did. They were named 3L80's though. Just because an old RPO list refers to it as a TH400 doesn't mean that's what GM called 'em at the time the truck was built. :)

I've owned one or two GMT400's so trust me when I make a statement you may not agree with, and it's followed by a wink or grin emoji, I *just might be joking instead of wrong*

Richard

I under stand Richard, I bought my '88 new when I worked at the dealership and we went through the whole THM 400 vs 3L80 when they started the new designations. The service manuals still referred to them as THM 400's as did the RPO codes in '88 and maybe '89.
 
Top