Newbie From Canada

[Sierraclassic403]

Hi all. Just discovered this site and registered today so thought I might make an introductory post. Found the site when I was researching transmission and axle information for my 81 Sierra Classic. I've owned the truck 22 years and its been great. A former 5.7 diesel, I dropped the 403 Olds motor in soon after I bought the truck and its been trouble free since. Transmission could use work though and I'm contemplating upgrading it to an overdrive, maybe the 2004R? The old TH350 has a non-functional lockup torque converter so the 403 is turning 2800 rpm at highway speeds. Its still doing at least 14 mpg on short trips winter driving but I figure it could only improve if I could drop the engine rpm to 2000 or lower. I'm wondering if anybody else has ever done this swap before and if it is a simple bolt in job. I know the 700R4 overdrive has the wrong bolt pattern for my Olds bell housing but the 2004R is supposed to be a direct match.

[kpruitt]

Cant help you with the trans. But welcome to the site.

[omegafiler]

Welcome to the forum, and nice lookin' classic GMC!

[pwall]

Welcome to

 

From out West I gather ?

[Sierraclassic403]

Welcome to

 

From out West I gather ?

Good guess. Right in the middle of farming country, Saskatchewan. I'll get my location posted along with an avatar after I get it figured out. This GMC is just a well preserved working farm truck that I hope to keep driving for a while yet. Its been in storage the past five years while I have been driving my 71 C!0. I'll give the C!0 a rest for a while now.