Side Yoke Upgrade, 1350 Enough?
Thread Starter
Heel & Toe
Joined: Jan 2021
Posts: 20
Likes: 0
Side Yoke Upgrade, 1350 Enough?
I'm currently wrapping up the last bits for my project C3 (1980) and it's time to upgrade the rear end. I'll be running a fairly hot 427ci SBC that should make ~550ft/lbs at the crank, paired with a short diff gear of around high 4's or low 5's with a gear vendors' overdrive. The car will see some weekend street driving, but mostly I want it as a track car that can handle some 1/8 and 1/4 mile passes with low chances of needing a tow truck to get home. I already have a 3" Chromoly driveshaft with solid 1350 u-joints in hand, so now need to figure out the other side of the diff.
To keep things simple and in-house, I'm sticking with the Dana 44 IRS. I've figured out most of my options thus far, but I'm having trouble finding info regarding the strength of the side yokes, in particular the new ones from the manual 80-81 and 82 cars (see the link below). It says they are made from hardened steel and I believe they run 1350 u-joints (?). So pretty much, does anyone have experience with these side yokes? Do you think 1350 u-joints will be strong enough for the half shafts given the short diff gear? Or should I look into going larger, like 1410 or 1480 u-joints with flange side yokes or something along that line?
https://www.zip-corvette.com/80-81-4...-yoke-new.html
Thanks for any input
To keep things simple and in-house, I'm sticking with the Dana 44 IRS. I've figured out most of my options thus far, but I'm having trouble finding info regarding the strength of the side yokes, in particular the new ones from the manual 80-81 and 82 cars (see the link below). It says they are made from hardened steel and I believe they run 1350 u-joints (?). So pretty much, does anyone have experience with these side yokes? Do you think 1350 u-joints will be strong enough for the half shafts given the short diff gear? Or should I look into going larger, like 1410 or 1480 u-joints with flange side yokes or something along that line?
https://www.zip-corvette.com/80-81-4...-yoke-new.html
Thanks for any input
Melting Slicks
Joined: Nov 2006
Posts: 3,413
Likes: 1,824
From: Apple Valley, MN
I know you stated you’re sticking with the Dana but you may want to seriously revisit that decision as the cast iron differentials are inherently stronger. Additionally, IMO, you’re much more likely to blow the Dana before you compromise a set of solid Spicer 1350s.
You also need to be thinking about the outer axles as well as you need to get that torque transferred to the pavement and the axles are, of course, part of that path.
You also need to be thinking about the outer axles as well as you need to get that torque transferred to the pavement and the axles are, of course, part of that path.
Thread Starter
Heel & Toe
Joined: Jan 2021
Posts: 20
Likes: 0
I know you stated you’re sticking with the Dana but you may want to seriously revisit that decision as the cast iron differentials are inherently stronger. Additionally, IMO, you’re much more likely to blow the Dana before you compromise a set of solid Spicer 1350s.
You also need to be thinking about the outer axles as well as you need to get that torque transferred to the pavement and the axles are, of course, part of that path.
You also need to be thinking about the outer axles as well as you need to get that torque transferred to the pavement and the axles are, of course, part of that path.
It's a fair point about the iron diff conversion and I'll consider it, but I guess it feels like a bit overkill for an automatic SBC build. It seems that people look down on the Dana 44 in the C3, although Gen 1 & 2 Vipers also run a Dana 44 and in my experience as a Gen 1 owner, I seldom see people having issues, despite the manual transmissions, even when running superchargers. Perhaps the internals are better and just in case, I luckily have a spare Viper diff posi/internals that can be transplanted into the C3's Dana 44.
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,990
From: Connecticut, USA
It sounds like you have done some homework. I don't think the 1480 axles will work with the spiders and 12 bolt spiders are larger than the DANA.
You will find, and I bet you have, some say the stock DANA will hold up fine and it has a bad rap. Maybe, some do run them hard but overall, they're not as good as the iron differential.
I sure wouldn't use one, but you can and probably will so good luck. You might not have a problem or you may blow it up, in which case you can convert to an iron built to your application.
You will find, and I bet you have, some say the stock DANA will hold up fine and it has a bad rap. Maybe, some do run them hard but overall, they're not as good as the iron differential.
I sure wouldn't use one, but you can and probably will so good luck. You might not have a problem or you may blow it up, in which case you can convert to an iron built to your application.
Drifting
Joined: Aug 2019
Posts: 1,510
Likes: 498
what's the difference between the 4sp and auto stubs ? Just U joint size ?
I did a bearing and reseal on one of my 44's and that case is awful gimpy around the bearing boss's and wouldn't surprise me if it was flexing under power with a good drag radial and some power , if the case is deflecting then you know the parts inside can't possibly stay in the correct alignment position with the other moving parts and you sir have a lot of engine
I did a bearing and reseal on one of my 44's and that case is awful gimpy around the bearing boss's and wouldn't surprise me if it was flexing under power with a good drag radial and some power , if the case is deflecting then you know the parts inside can't possibly stay in the correct alignment position with the other moving parts and you sir have a lot of engine
Instructor
Joined: Jun 2023
Posts: 201
Likes: 66
From: Orlando, FL.
Even any Dana 44 for that matter, if I was going to the trouble of changing the center section. Not the only issue, but make the observation and consider the potential capability of the ring and pinion particularly with "high 4's or low 5's" gearing.
Because, if you car really "hooks & books", it breaks!
Scott.
