In the 90 gmc sierra what transmission is used?

[sniperlif3]

Well ihave a 1990 gmc sierra 2wd that has a chevy 350 small block and im not sure whether they used the 4L60E/4L60 transmission in the 90 model or if they used the 700R4. Would someone be able to help me out by telling me which one i have?

I am also curious, would the 4L60 and 700R4 fit on all of the small and big blocks? Also would the 4L80E work with a small block, and if so what is the benifit?
Or would it be the TH400 or TH350?

 

[Z15]

could be a THM700-R4 or a THM400

 

[Molson02536]

Well ihave a 1990 gmc sierra 2wd that has a chevy 350 small block and im not sure whether they used the 4L60E/4L60 transmission in the 90 model or if they used the 700R4. Would someone be able to help me out by telling me which one i have?

I am also curious, would the 4L60 and 700R4 fit on all of the small and big blocks? Also would the 4L80E work with a small block, and if so what is the benifit?
Or would it be the TH400 or TH350?

You have a 4L60 which is the same as the 700R4, just make sure that the 4L60/700r4 is the one for your Sierra. The 4L60/700r4 was also used in the S Blazers/Jimmys and Astro vans, the ones used in the lager trucks like your had a different governor and boost valve for different shift points and transmission line pressure.

The E at the end of the 4L60E and the 4L80E stands for electronic and has electronic shift solenoids which is controlled by your PCM. You can still use a 4L60/700r4 transmission and do the upgrades like the sun gear up graded to the 5 planetary gear system in a 4L65E rather then the 4 which is in the 4L60.

Your better off using the 4L60 transmission rather then the 4l80E. The parts are more readily found and you can make the 4L60 transmission bullet prof, give me a PM when your ready to rebuild and 4L60/700r4 transmission.

Good luck and keep us posted