Regearing Advice... What do I need?

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JBswth

Full Access Member
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Jan 24, 2022
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Location
Vallejo, California
First Name
James
Truck Year
1973
Truck Model
C25
Engine Size
292 cubic inches
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...
4:10 or 3:73 is what you need if you have an automatic are towing. If you have a stick, 4:10 or maybe even 4:56 if you have the biggest tires. The LS is more of an RPM motor than the regular Small Block, so you need shorter gears.

J. B.
 

shep151

Junior Member
Joined
Oct 6, 2023
Posts
21
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Location
Columbia River Gorge
First Name
Zach
Truck Year
1978
Truck Model
k10
Engine Size
350
How long until you do the 4L80? Do you have to modify the transmission tunnel on our cabs? Someday if (or more likely when) my 700r4 craps the bed I'll probably go that route.
4L80E is already in, from my previous truck, a 2005 2500HD. No mods to the tunnel, it fit great.
 

shep151

Junior Member
Joined
Oct 6, 2023
Posts
21
Reaction score
51
Location
Columbia River Gorge
First Name
Zach
Truck Year
1978
Truck Model
k10
Engine Size
350
FYI: To minimize downtime and just get it DONE, I found a reputable shop and am paying to have it done. Can't wait to pull the boat back up to my favorite lake and see how she does. Considering that the drivetrain will be identical to the donor, my 2005 2500HD, and the K20 weighs almost a ton less, it should be nice.
 

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