GM Truck Club Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
I am thinking of trying to change the gear ratios in either the transmission or rear-end or both to make better use of my low end gears. Currently first gear is so low that I start from a stop in second. Obviously I have a manual transmission, it is a 4spd with OD. My truck is an '89 GMC Sierra SLX 2wd. Although I do have aftermarket wheels on the truck the outer circumference of the tires is almost identical the factory tires (my current tires are just wider 275 vs 225). Any suggestions?

Thanks,
 

·
Registered
Joined
·
8,623 Posts
What rear gears do you have in it now? If unknown, get your rpo codes off your glove box door, & plug them & your vin number into the ww.compnine.com site, or if you're due for a rear gear fluid change pull the rear end cover plate off & count the number of teeth on the ring & pinion gears
 

·
Registered
Joined
·
7,979 Posts
Do a search of the site for RPO codes, after that you will have an idea where you are sitting, since the 350TBI isnt the most powerful motor you may have other things you can do as well that wont hurt your milage depending on your current ratio.
 
1 - 4 of 4 Posts
Top