Newbie needs your help

[Philipf9]

Ok guys, I'm a newbie and have gotten into the square body's to help my son with his first truck. So please be kind and help me out. I don't understand all the tech talk but I'll try. My son is looking to buy an 86 k10. It's had been altered and not stock. It has a 350 small block, 4 speed manual with granny gear. The axels have been changes from 1/2 to 1-ton with 4.10 gears, 35" tires and 4" lift. From my driving it, I seem to go through the gears pretty quick (2-4). The rpm gauge is after market so I don't know if I trust it, but at 45mph, it's seems to be running hard. At 60, it's screaming pretty loud. The aftermarket gauge says its at 3200. I guess my two questions are, is this normal sounding or does something odd about that setup jump out to you? Is this a decent setup for a 16 year old to cruise around town and on occasion cruise down highway?

Thank you in advance for all your help and advice!

 

[RetroC10Sport]

Sounds about right, with the 35s, 4.10s and SM465 trans, it's not going to be running any lower RPMs at 60, for sure.

 

[Philipf9]

I'm not sure exact rpm but its screaming. Could I put in a 5 speed tranny or even an automatic 5 speed or overdrive?

 

[Philipf9]

Also wanted to ask, could/should
I go back to 1/2 ton axels? I think the truck was originally done for pulling but I want it more for cruising around town

 

[da_raabi]

1/2 vs 1-ton axles will make little difference in drivability. Swapping back really would not be worth it unless you are trying to squeeze gas mileage or something - but if you are buying a lifted 80s square gas mileage must not be a concern!

Being that the truck is a 4x4, you are slightly limited on transmissions. I don't have much 4x4 experience, but I believe you run into problems with later transmissions due to the transfer case being left vs right side drop. Updating the transmission would likely require a different front axle.

I'd leave it as is - or maybe look into taller tires or (even better) more highway friendly gears in the axles. 3.73s would likely help a LOT.

 

[VAL]

Check your gearing, there are some 1 ton axles that have 4.56 gears. I believe the CUCV have that ratio.

 

[kickdeez]

That is normal for that setup. There is no easy/cheap fix for lowering RPMs. You are either looking at swapping transmissions, or swapping axle gears, or a combination of both.

The most straight forward transmission swap (i use that term loosely) would be to put in a NV4500 transmission. It is basically the same thing as the transmission that is currently in it, but with an additional gear for overdrive. It won't be super cheap, and you will have to make some modifications. Bellhousings and transfer case adapters can get very expensive.

Swapping axle gears would be another option, and likely cheaper, but it is very important to set up the gears correctly. This could be difficult if you don't know what you're doing. Even then, if they are chevy 1 ton axles, your gearing options are limited. Swapping to 3.73s will definitely make a difference in RPMs, but it will still run pretty wide open on the interstate.

At the end of the day, you could really put whatever transmission/transfer case/axle/tire combination in that you want, but be prepared to fork out some money, and put in some elbow grease, because it won't be a cheap and easy endeavor.

With all that being said, I currently run a SM465 transmission with 3.73 gears. I drive it around town, and tow on the interstate with it. The biggest problem with the setup is she drinks gas. If you can live with that, I say run it. Tell your son to save his money for an eventual transmission swap down the road, if that's what he wants to do with it.