rear end ratio or other issues?

[doublearrow]

Ive got an 87 silverado 4x4 i bought as a daily driver 4 years ago. I know in stock form these are low hp trucks, but since the day ive bought it ive had an issue i think is more than a power issue.
It has 33" tires with what i assume are the stock gears. 3.08? I cant find a definitive answer?
If someone is driving 65 in 70 and i pass them i need a looooonnnggg clear path to get up to speed. Its almost comical and annoying to other drives when they think im just riding beside them in wrong lane. When towing a 16 foot open empty trailer or 10 foot enclosed empty trailer i cannot go over 50 mph with the gas pedal on the floor. I dont tow a trailer alot 3 or 4 times a year. The transmission went out last week and is being replaced. Ive not trusted the transmission since i bought it due to the color of the fluid. I had hoped the transmission might be the issue but the mechanic doesn't think so.
Would the stock gears be my issue? Or is there something else? Or am i at the limitations of the truck? If gears what is recommended for 33" tires? Daily driver, hunting truck, dont play in the mud much just when hunting. Any help would be appreciated. Thanks Ryan

[LONGHAIR]

It very well could be just the gears. The early overdrive trucks were geared way to high, trying to increase fuel mileage numbers. This made them rather lifeless in the first place, then adding bigger tires makes it worse.
That is not saying that you may not have other issues too, but the gears are likely a big part of it.

[Keith Seymore]

Check the SPID label in your glovebox.

If your truck is equipped with the base axle then it should show "GQ1" and no ratio will be specified.

Follow this link to the generic info packets in the GM Heritage Center archive

http://www.gmheritagecenter.com/gm-h...tion-kits.html

Open the pdf file for '87 Chevy pickups and find the powertrain charts. These will show you what the base axle ratio is for your particular combination.

If it has an optional ratio then it will show the ratio and a description:

GU6 = 3.42
GT4 = 3.73

That's assuming it hasn't been changed since it was built.

And -yes - a 3.08 would be a particularly bad ratio in your case.

K

[nekkidhillbilly]

3:08 is a bad ratio in anything with overdrive.

[Driver4r]

For towing a trailer, and running 33"s i would go 3.73 gears. Your OD will still be a nice lower rpm.

[doublearrow]

Thanks for the help everyone. Looks like i will be doing a gear swap.

[TwoFiftyShifter]

What tranny do you have?

[Ski-me]

What ratio did you find? 700r4 tranny?

[doublearrow]

700r4 and best i can tell from literature is a 3.08 ratio. Father in law has transmission in the truck but havent gotten it back yet.

[doublearrow]

Very possible theyve been changed, but from what i can tell other than tire size the truck was replaced with stock if there were ever any issues.