Regearing Advice... What do I need?

[shep151]

So... After pulling my 5000 lbs boat up to my favorite lake for the first time with Bubba, my newly LS swapped 1978 K20, I've decided those 3.42's have got to GO!
Having no plans to lift the truck or go to anything more than *maybe* 33's (Currently 32's) I'm going to put 4.10's in it, like the donor had.

Running a 14 bolt rear, GM corporate front. Looking for all inclusive kits that'll get me back on the road in a weekend.

Does anyone have a link to good kits for the regear?

Any advice? First time on this job...

 

[TotalyHucked]

4.10s will be perfect. I've had 2 NBS trucks with factory 4.10s and 33s and it was a great combo. When I regeared my truck, I got everything from Quick Performance. They're great to work with. Not sure if they deal in front axle stuff or not but if they do, that's who I'd recommend.

 

[Bextreme04]

So... After pulling my 5000 lbs boat up to my favorite lake for the first time with Bubba, my newly LS swapped 1978 K20, I've decided those 3.42's have got to GO!
Having no plans to lift the truck or go to anything more than *maybe* 33's (Currently 32's) I'm going to put 4.10's in it, like the donor had.

Running a 14 bolt rear, GM corporate front. Looking for all inclusive kits that'll get me back on the road in a weekend.

Does anyone have a link to good kits for the regear?

Any advice? First time on this job...

It's gonna be a hard grind to do both in a weekend. You will definitely want a crush sleeve eliminator kit for the 14 bolt. Trying to crush down a sleeve is a monster of a job on a 14 bolt. You need at least a 20 ton press or be able to put many hundreds of lb-ft of torque on it just to start the crush. You'll also want to sand out the inside of the old bearings to allow you to slide them on and off easily to properly set your preload and backlash shim sizes.

I already had 4.10's on mine, so I just rebuilt it using a USA Standard gear kit and Yukon Grizzly locker that I bought locally for a steal. The USA Standard kit had Timken bearings in it and has worked perfectly so far.

 

[Ricko1966]

First time doing this,give yourself a weekend for each diff. Next time you'll be able to do it in less than a weekend. But not likely first time. If your new pinion and old pinion have the same depth,make yourself a go/nogo gauge. Bolt a piece of angle across 2 differential cap bolts drill a hole that will allow you to run a piece of all thread through and touch the face of the pinion gear,lock the all thread in place with 2 nuts. Now back your all thread back about .030 measure it with feeler gauges. Now going back use your old shim and your go/nogo gauge, get out your feeler gauges is your clearance .030? A little math using your old shim and .030 will tell you what size shim you need. As Bestreme04 said,absolutely buy a crush sleeve eliminator,it will make your life so much easier.

 

[SquareRoot]

LS Swap.........oh wait

 

[Old Guy Bill]

Yukon Gear, East Coast Gear Supply, USA Standard Gear, Summit, etc.. they all have bearing/seal & gear sets. Be sure to identify the current differentials in each before ordering.

 

[Camar068]

Yukon Gear, East Coast Gear Supply, USA Standard Gear, Summit, etc.. they all have bearing/seal & gear sets. Be sure to identify the current differentials in each before ordering.

No complaints from the Richmond Excel gears I've got. I shoulda listened to @HotRodPC and went 4.10 instead of 3.73.

 

[HotRodPC]

Richmond are good gears. Most of the street racers way back when usually used Richmond gears for the better quality builds, and the guys who had to cheap out a bit used Zoom gears. Not even sure they're in bidness. May have been bought out by someone but I don't see or hear of Zoom gears anymore at all so I'd imagine they're all done quite some time ago.

 

[TotalyHucked]

I will say I was warned that Richmonds, when you go deeper than 3.73 are noisy. I can confirm, my 3.90 Richmonds do have a minor howl. Nothing bothersome, can't hear it over the exhaust or radio anyway lol

 

[gmbellew]

I have 3.73 in my v1500 burb (350tbi and 4L60), and don't think the cost is worth it to swap to 4.10 for ~32in tires. Right now i have a cruising RPM of about 2100rpm on the hwy at 75mph and it is certainly plenty serviceable around town also. Although I'd prefer 4.10, its just not that big a jump over 3.73 that are already in both axles. 4.33ish would put me at the original gear ratio/tire size, but is an oddball gear. I thought briefly about jumping to 4.56, but it doesn't bother me enough to justify the cost of regearing 2 axles.

now if I had 1 axle instead of 2, I'd maybe have already made the jump from 3.73 to 4.56. or if I didn't already have 3.73, I'd probably already have jumped to 4.10 bc the truck would be struggling with larger tires.

 

[Hunter79764]

2 things come to mind... Swapping the rear gear is going to be your time crunch, if your axle has other issues in general, can you find a lower mile complete axle with 4.10's and swap the assembly? The front can take more time, as long as you don't use 4wd in the meanwhile...
2nd thing, I'm sure you're aware, but there are 2 different 14 bolts, the semi-float and the full-float, make sure you have the right one in mind on parts buying etc.

 

[Ricko1966]

2 things come to mind... Swapping the rear gear is going to be your time crunch, if your axle has other issues in general, can you find a lower mile complete axle with 4.10's and swap the assembly? The front can take more time, as long as you don't use 4wd in the meanwhile...
2nd thing, I'm sure you're aware, but there are 2 different 14 bolts, the semi-float and the full-float, make sure you have the right one in mind on parts buying etc.

I can definitely swap gears,faster than I can swap a rear end. And he will need to learn this skill anyway if he's going to do both and it eliminates the possibility of buying the wrong rearend. Glad you brought up driving on just the rear diff, that's what I was thinking in my previous post,I just assumed everyone knew that,I'm glad you considered he may not. I gotta quit making assumptions. Actually no matter which one he does first he can still drive on just the rear,but if he does the rear first he will get to see the difference immediately.

 

[75gmck25]

The 4.10 14 bolt was a common gearing in early 70’s 3/4 and 1 ton squarebodies. I would search for one and just do a swap for the rear. You might even find the matching front axle, which would probably be a Dana 44,
Find a 14 bolt without gov loc, since then it’s easier to add a limited slip or locker later on.

Swapping the entire axle might take a little longer, but it’s all very simple bolt-on mechanical skills. Nothing as complicated as figuring out crush washers, gear wear patterns, etc.

 

[Grit dog]

So... After pulling my 5000 lbs boat up to my favorite lake for the first time with Bubba, my newly LS swapped 1978 K20, I've decided those 3.42's have got to GO!
Having no plans to lift the truck or go to anything more than *maybe* 33's (Currently 32's) I'm going to put 4.10's in it, like the donor had.

Running a 14 bolt rear, GM corporate front. Looking for all inclusive kits that'll get me back on the road in a weekend.

Does anyone have a link to good kits for the regear?

Any advice? First time on this job...

My advice. If your axles are both good shape, bring your truck over here. I’ll literally you swap your 3.42s for the kids 4.10s. For free.
If you paint them black and swap my brakes and hubs (unless yours are nicer lol) I’ll provide the beer too.
Don’t even need to bring tools.
You must have overdrive or you wouldn’t be swapping.

 

[shep151]

My advice. If your axles are both good shape, bring your truck over here. I’ll literally you swap your 3.42s for the kids 4.10s. For free.
If you paint them black and swap my brakes and hubs (unless yours are nicer lol) I’ll provide the beer too.
Don’t even need to bring tools.
You must have overdrive or you wouldn’t be swapping.

Tempting as that is, I'm not 100% confident in the rear axle overall. The PO had a tendency to haul HEAVY and I have a slight wheel vibration that I've isolated to the right rear, but can't see the cause. I've gone over all the usual suspects and am coming up blank.

So I've decided to have a reputable shop regear the rear diff and go through the whole rear axle from drum to drum so I'm starting with a clean slate. Later I'll do the front diff, it's a 10 bolt corporate.