500 HP and a two piece drive shaft

[70CHEVYBB]

I am building a 468 for my 70 lwb. I am not sure if the two piece drive shaft will holt up. Anyone ever have problems with this?

[kelsfine69]

I have the 454 LS7 in my 69 lwb. Had the driveshaft tubes replaces with a stronger driveshaft tube(a lot heavier) its harder on support bearings but other than that never had a problem. Would like to redo it with something lighter? but dont know whats available now. I had this done 20 years ago when this was the only option...

[70blackfish]

i use to break my center support all the time with a good shifting turbo 400 trans and a stock 327..they didnt make the aftermarket center support back then.

[Lee H]

As light as these truck are you should be OK, at least to start with, unless there are a lot of neutral drops in your future or your going with some very sticky tires. Any competent drive shaft shop can make you one that will hold up when your ready to plant all that horse power.

[brad_man_72]

I build driveshafts for pretty much anything from a unimog to land speed cars, and limos.
We build driveshafts for 600hp stock cars using the same size tubing, weld yokes, and ujoints that came in our trucks from the factory. We also drill a 1"hole in the center of the weld yoke with no problems.

Hp, torque, and mph will not hurt a carrier bearing. Vibrations kill carrier bearings. Most people have zero clue how to replace a carrier bearing and maintain the ballance of the driveshaft. This is the only reason people have any problems with our carrier setup.

600 hp is pushing it on 40 year old parts, mainly the stub and bolt on yoke. Its pretty easy to remake a stockish driveshaft with cheaper and better parts than were available 40 years ago.
That being said its even cheaper to build a nice one piece driveshaft.

Whatever you do don't use precision brand ujoints and be sure to have the shaft ballanced.
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[Longhorn 70]

Originally Posted by brad_man_72

Whatever you do don't use precision brand ujoints and be sure to have the shaft ballanced.
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That its so true! They do snap easily in the center of the cross. You'd think FM would build a better product.
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[mmsidaho]

I asked a similar question at the driveline shop where I got my driveline balanced a couple of weeks ago. They indicated the carrier bearing is the weak link. I had already purchased a regular (stock) carrier bearing to use in my rebuild, but the shop indicated there were more heavy duty carrier bearings available (more expensive though). The shop did run a weld down each side of the two top plates for me to strengthen it up.

[brad_man_72]

Originally Posted by mmsidaho

I asked a similar question at the driveline shop where I got my driveline balanced a couple of weeks ago. They indicated the carrier bearing is the weak link. I had already purchased a regular (stock) carrier bearing to use in my rebuild, but the shop indicated there were more heavy duty carrier bearings available (more expensive though). The shop did run a weld down each side of the two top plates for me to strengthen it up.

We do usually weld the seams also. No reason to drop $100 on a billit/neoprene support, the originals lasted 30+ years, theirs no reason that one on a properly rebuilt and ballanced shaft wouldn't last 30 more.

Precision joints aren't really that much weaker than any other joint with a drilled cross. The problem is the poor tolerances the cups fit looser than any joint I've seen and when installed (the best you can with the parts in the box) their is excessive endplay making the shaft impossible to ballance. But hey they have a lifetime warranty
The loose tolerances does make the joints wear faster, as well as the poor finish on the cross surface, the loose tolerances also increase shock loads and disperse load over a smaller area.

I recommend spicer 5-1310 they are a non greaseable solid cross joint that most manufacturers use that usually last 100k-200k miles. That's what I have in my truck.
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[88fordf150]

I see Summit Racing has a 3" Driveshaft kit on sale ( SUM-730404) for $260.96. Comes with 1350 u-joints and one end welded, I guess you cut to length and weld the other end yourself? But is it worth it?

[brad_man_72]

Originally Posted by 88fordf150

I see Summit Racing has a 3" Driveshaft kit on sale ( SUM-730404) for $260.96. Comes with 1350 u-joints and one end welded, I guess you cut to length and weld the other end yourself? But is it worth it?

Since a 1350 joint won't fit the rear end in these trucks and most do it yourself driveshaft welds I've seen result in having to at least buy a new piece of tubing, 2 cut and welds and a ballance I will say NO.
Considering we can build a shaft exactly to your specs, weld both ends (straight (within 0.010" and in time), ballance, paint, and ship it to your house for less id say NO again definetly not worth it in any way, shape or form.

Did they say what kind of ujoints, I'm pretty sure summit sells precision (junk) and we could use spicer non greasable solid cross ujoints for less than the $260.
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[88fordf150]

Originally Posted by brad_man_72

Since a 1350 joint won't fit the rear end in these trucks and most do it yourself driveshaft welds I've seen result in having to at least buy a new piece of tubing, 2 cut and welds and a ballance I will say NO.
Considering we can build a shaft exactly to your specs, weld both ends (straight (within 0.010" and in time), ballance, paint, and ship it to your house for less id say NO again definetly not worth it in any way, shape or form.

Did they say what kind of ujoints, I'm pretty sure summit sells precision (junk) and we could use spicer non greasable solid cross ujoints for less than the $260.
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I thought this might be the case. Thanks

[ffk]

as soon as i get my motor and trans in,,ill get hold of you for a one piece drive shaft for my 68

Originally Posted by brad_man_72

Since a 1350 joint won't fit the rear end in these trucks and most do it yourself driveshaft welds I've seen result in having to at least buy a new piece of tubing, 2 cut and welds and a ballance I will say NO.
Considering we can build a shaft exactly to your specs, weld both ends (straight (within 0.010" and in time), ballance, paint, and ship it to your house for less id say NO again definetly not worth it in any way, shape or form.

Did they say what kind of ujoints, I'm pretty sure summit sells precision (junk) and we could use spicer non greasable solid cross ujoints for less than the $260.
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[darush01]

Ive thought about a one piece or just upgrading to a better 2 piece but my old one works fine for now
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[brad_man_72]

Originally Posted by darush01

Ive thought about a one piece or just upgrading to a better 2 piece but my old one works fine for now
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If it ain't broke, fix it till it is!
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