| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,156 Posts1,057,018 Members48,460 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Oct 2019 Posts: 14 'Bolter | | 'Bolter Joined: Oct 2019 Posts: 14 | I got a 1st series '55 Chevy 3600, 8 lug, 3/4 ton truck. I'm in the process of swapping out the front end to 6 lug and will soon be moving on to the rear end. The '55 is an open drive shaft. Do any of you know what 6 lug rear differential years with open drive shaft I can use on my '55?? Thank you all again!! | | | | | Joined: Mar 2010 Posts: 10,303 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,303 | I would look for a '67 -'70 half ton truck rearend. They are 12 bolt with the correct 6 lugs and the width is very close to correct.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: Oct 2019 Posts: 14 'Bolter | | 'Bolter Joined: Oct 2019 Posts: 14 | Thanks for letting me know about that 52Carl I didnt know that! | | | | | Joined: Jan 2000 Posts: 2,074 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 2,074 | I used a 65-66 truck rear end on my 46, not to wide, lots of available ratios! | | | | | Joined: Oct 2019 Posts: 14 'Bolter | | 'Bolter Joined: Oct 2019 Posts: 14 | I used a 65-66 truck rear end on my 46, not to wide, lots of available ratios! Thanks JiMerit Boltr#43 and 52Carl. I'm very new with this driveline topic. If I end up getting a rear end from a '60s truck with the correct width do I have to worry about swapping out my transmission because of the gear ratio? I currently have the stock 235 engine and tranny. I assume the gear ratio from a later truck differential will be different than the the 4.56 gear ratio that came stock with my 3600. Also can I use my current drive shaft? Thank you very much for imparting your knowledge on this topic! | | | | | Joined: Mar 2010 Posts: 10,303 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,303 | You might be able to use your current drive shaft. GM is famous for continuity throughout many years of production.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: Oct 2019 Posts: 14 'Bolter | | 'Bolter Joined: Oct 2019 Posts: 14 | Ok got it 52Carl I'll let you know what I end up using..crossing my fingers the drive shaft will work with the new rear end. I'm glad I'm not restricted to the '55 1st series.
Last edited by D$TROYER; 10/20/2019 8:47 PM.
| | | | | Joined: May 2015 Posts: 11,150 Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums | | Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums Joined: May 2015 Posts: 11,150 | Shouldn't be an issue with the driveshaft. Worst case, it might need to be lengthened or shortened. If it's just a u-joint fit issue, u-joints with different size cups are available at any good driveline shop.
Kevin 1951 Chevy 3100 work truckFollow this saga in Project JournalPhotos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together. | | | | | Joined: Oct 2019 Posts: 14 'Bolter | | 'Bolter Joined: Oct 2019 Posts: 14 | Klhansen thanks for your input. Do you know if I have to worry about a transmission swap since the gear ratio will most likely be different? | | | | | Joined: May 2015 Posts: 11,150 Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums | | Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums Joined: May 2015 Posts: 11,150 | Unless you're looking at an overdrive transmission, it won't make a difference. Most transmissions are direct drive in top gear.
Your rear axle ratio is 4.57 which is pretty low. Later axles are likely a higher ratio (eg.4.10, or even higher) which would help keep your highway cruising engine RPM down. Unless you're pulling stumps, you don't need a 4.57 rear axle ratio, although you could find an overdrive transmission, which would allow you to use a higher numerical ratio axle and still cruise down the highway at comfortable engine RPM's.
Kevin 1951 Chevy 3100 work truckFollow this saga in Project JournalPhotos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together. | | | | | Joined: Oct 2019 Posts: 14 'Bolter | | 'Bolter Joined: Oct 2019 Posts: 14 | Unless you're looking at an overdrive transmission, it won't make a difference. Most transmissions are direct drive in top gear.
Your rear axle ratio is 4.57 which is pretty low. Later axles are likely a higher ratio (eg.4.10, or even higher) which would help keep your highway cruising engine RPM down. Unless you're pulling stumps, you don't need a 4.57 rear axle ratio, although you could find an overdrive transmission, which would allow you to use a higher numerical ratio axle and still cruise down the highway at comfortable engine RPM's. Thanks for the info Klhansen that answered my question!
Last edited by D$TROYER; 10/22/2019 5:02 AM.
| | |
|
|
| |
