The Stovebolt Site Forums The Shop Area Engine Shop axel swap

Hello,

I searched for a bit and have yet to find what I am looking for so I figured I would just ask.
Sorry if this has been covered before.

I would like to swap axels from my daughters 64 K20 to a new set that would allow for better highway driving about 70 MPH.
Additionally I would like it to have power steering and disk brakes in the front.

I was told by a "guy" that swapping the axels would be the best way to accomplish these things.

My questions are;
Is he right?
what year truck axels should I use for the swap?

Thanks in advance for any help on this post and what I can only assume will be many to come.

Ned

????? need more info.whole axels or ring & pinions?

For the front, I would like to swap out the whole axel and replace it with a newer one that has disk breaks and power steering.

In the rear I would be happy with a ring and pinion replacement, if there is one. I was told that there were very few options for replacement ring and pinion sets for a 3/4 ton rear end.

The frames are very similar on all K20s up to '87 so adapting parts from that new isn't real hard.

It isn't so much as ring and pinion are hard to find for that rear, its that the only set anyone really wants is rare as hen's teeth.

Three ratios were available, 5.13, 4.57 and 4.11 (I may be slightly off in each of those), but the one people usually want is the 4.11 and few survive.

OldSub,

Thanks for the info, last night I was honing in on what you have just stated.

I wonder if I were to switch the front axel out with an axel from a newer K20 if I could also switch the rear axel out from the same newer K20.

My hope is to get the truck to a gearing that would allow it to be driven around 70 miles an hour without keeping the RPMs too high.
Not to mention fuel economy would be a consideration.

Unfortunately I have no knowledge on gear ratios to know what would accomplish these goals.
I have been spending all of my free time trying to learn from the internet.
But so far I am as dumb as I sound.

Thank you for your help so far any more information you can provide me is greatly appreciated.

Well the usual approach is to determine at what RPM the motor is going to be happiest and then assuming that answer doesn't cause other problems, you try to balance your overdrive, differential ratios and tires.

There are numerous calculators that will tell you speed at RPM at different tire sizes and ratios.

You are trying to get the balance right between a lot of factors and its not always easy.

You have to start with that judgment call regarding the optimum RPM for your priority usage.

I'm happy to dialog at depth about this, but today have run out of steam. Keep the dialog going.

Sell that 4wd and get a 2wd truck for better fuel economy. Putting higer gears in a 4wd is sacrilege! If you really need to get the rpms down, use an OD transmission in front of the transfer case. Is the transfer case divorced or married to the transmission?

The transmission is divorced from the transfer case. Had not thought to swap the transmission out. defiantly don't want a 2wd truck, we are out in the sticks and have to get through the mud and snow sometimes.

Right now I am thinking of just getting it running as it is then further exploring the axel swap thought if need be. Kinda think I will be looking into it later though.

Thanks for your guys' input