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3.72 rear for 1949 kb2

PostPosted: Mon Aug 27, 2018 9:26 am
by tinnlizzi
Hello! I am looking for the optional 3.72 rear end for my 1949 international kb2. I believe it would be 41 teeth on the ring, 11 on the pinion. It should be stamped as well on the pinion shaft, by the u-joint. You can also determine ratio by chocking one wheel, and turning the other 10 times, counting the driveshaft revs. I guess I realize that this is pretty hard to find... is there another ring and pinion set that would bolt right in (GM Willys, Ford, etc? ) ..? I haven't found any manufacturer that makes anything like this (my ford model A has a high speed rear end kit from Little Dearborn) ...Maybe another year that is compatible? I've checked Windy Hill, French Lake, and others here in Minnesota..I've got the 4.18 in right now, and she pulls uphill pretty well with a fresh engine and slightly over sized tires, but I want a little more top end. Getting a set custom cut is just waaaaaay too expensive for a production run of one.....wonder what kind of market there is for this....Thanks, and take care! Mike

Re: 3.72 rear for 1949 kb2

PostPosted: Mon Aug 27, 2018 12:00 pm
by lbesq
Mike, That gear set is almost as elusive to find as "drums" for the 6x7 1/4 bolt spacing on the larger pickups.

Re: 3.72 rear for 1949 kb2

PostPosted: Mon Aug 27, 2018 12:54 pm
by 41Woodie
See my post about swapping 4.18 rear axle for a Ford Explorer 3.55 8.8
viewtopic.php?f=7&t=8931&p=68224&hilit=ford+explorer#p68224
Ford Explorer 8.8 3.55 rear axle to K1

Re: 3.72 rear for 1949 kb2

PostPosted: Thu Aug 30, 2018 12:28 am
by tinnlizzi
Thanks for the replies! ...I had heard of swapping out the axle for a Ford...that may be a good option. Parts are really harder to find than I thought.. ( I am using a vintage 6 volt Ford fuel sender and oil pressure sender...and one of my valve springs is off an old Jeep..a half helix shorter and wound the opposite way, but it works great!!....) I know a lot of guys seem to be either rodding or modifying these trucks....more than are restoring them... seems there would be a few extra rear ends left behind in the process...was the taller gear set just not as popular an option back then? Mike

Re: 3.72 rear for 1949 kb2

PostPosted: Thu Aug 30, 2018 10:19 am
by bedrockjon
Supposedly the 3.73 was installed in 3 speed column shift, and 4.11 in 4 speed floor shift,

But as always nothing is absolute with IHC

Re: 3.72 rear for 1949 kb2

PostPosted: Tue Sep 11, 2018 10:25 pm
by tinnlizzi
truck resized.jpg
Pic of how she looks!

Re: 3.72 rear for 1949 kb2

PostPosted: Wed Sep 12, 2018 12:13 am
by lbesq
Nice!

Re: 3.72 rear for 1949 kb2

PostPosted: Wed Sep 12, 2018 8:19 am
by AZD
I have wondered if the 3.73 came in 3-speed trucks. At least one trans model has a ratio of 3.5 or so in first gear. Seems like a good candidate for a higher rear ratio beacause it’d be similar to a 4.11 axle with the 3.09 second gear on the 4-speed trucks. Just a thought.

Re: 3.72 rear for 1949 kb2

PostPosted: Tue Nov 26, 2019 8:52 am
by grospetit
hello to you. I see that many of you are using diff. explorer 8.8 of 3.72, on my side I used a diff. from gmc canyon or colorado of 2005 --3.72--with wheels of colorado of 2010 to have a 16po and installed the same tires that I had on the truck and everything is perfect the springs arrives at the right place and the drive shaft too and the Intalled width is the same as the front wheels. It costs $ 1200.00 $ 500.00 for the crankcase, and new drums, brake bands, hand brake cables, wheel cylinders and a new drive shaft. the width is the same as the front wheels ext. 65 ''
i did use google for traduction
Marcel
ps: difference between 3.72 and 3.55 is about 2 miles per hrs