55.2-59 Best Driveshaft to cut down for LS swap and C4 Vette Rear

[daveshilling]

Gang, it's driveshaft time.... and I would love to re-use an old one and just have it cut down. Better for the planet, and better for the wallet.

I'm going from a 4L60e to a Corvette Spicer 1310 rear. 2.5" diameter preferred for clearance... If 3" is the only option, I may need to trim a crossmember but I can manage that if I must.

I need to get something longer than say 54" to have it cut down by a local shop. Has anyone found a good match in a used driveshaft for an application like this?

The driveline also said to avoid swaged (tapered) if possible...or to make sure its so long that I can cut that off, but trucks with super long driveshafts are usually 4" or more.

[mongocanfly]

ive had driveshafts shortened, and built from scratch...
things to consider are tube thickness, diameter, and material are based on hp and rpm .. i would talk to a driveshaft shop and let them recommend ..

[daveshilling]

Originally Posted by mongocanfly

ive had driveshafts shortened, and built from scratch...
things to consider are tube thickness, diameter, and material are based on hp and rpm .. i would talk to a driveshaft shop and let them recommend ..

A driveshaft shop recommends I pay them to make one for me, or they will cut one down if I do the rest of the homework.

An OEM driveshaft comes out of a car/truck that already has that information accounted for by GM, right? And shorter is stronger due to physics, so shortening is in my favor.

Just looking for a good used OEM donor recommendation if anyone has one!

[mr48chev]

This should be a reasonably easy to find driveshaft that you can cut down and I'd think that Joedoe can confirm the measurement reasonably easily.
For show and tell and what to look under only not a suggestion to buy. https://fortwayneclutch.com/product/...-sku-15088443/

Here, this is a link that you will like. That burb unit he mentions might be pretty close.
Good info worth saving. https://www.s10forum.com/threads/dri...stions.531690/

[fauXGT]

Kinda what I'm looking at... also for the least expense, and built to handle the power. What my local shops can offer is if you give them the measurements, the original driveline or spline count to the trans, ( shortening a C4 driveline to fit the original trans going to original rear end), giving them the original yoke and they can shorten, balance and have it ready to bolt in.
If they can re-use any part of a project, that is considered recycling....right?

[_Ogre]

stock driveshaft should go into the trans, just have the shop weld on the c4 end
i had the stock shaft shortened to fit the 700r4

our trucks are so light that you can't get enough traction to twist one in half
unless you try to light em up with 1000lbs in the bed

[jwhotrod]

its not only whether or not you can twist it off, but also there is a little part of physics lurking out there called critical speed and 1/2 critical speed. that is when the driveshaft diameter is too small for the length and it causes terrible vibration that will shake the car to death. the drive shaft starts to swing like a jump rope. and it doesnt have to be high horsepower either. this occured in my friends 61 Buick special with a 180hp v6 in it, the car was great up to 60mph, but when he put a tremic 5 speed in the car ang got it up to 75 in overdrive the car started this vibrating that would shake your teeth out. Greg Frisch at inland empire driveline helped him fix it. their website has a ton of great info about driveline dimensions and setup.

[mr48chev]

An 80 Malabu drive shaft is 57.875. They are three inch though.

There may be a battle with the rear U joint not matching though.

This shows everything that is the same length. That would give you and easy to find driveshaft that had a few inches to cut off. https://www.ebay.com/itm/325063476507

[Hcb3200]

got mine with matching yoke from recycler to have cut down.
Saved a ton the yoke. new was triple the cost of the used shaft with yoke.

[daveshilling]

Originally Posted by _Ogre

stock driveshaft should go into the trans, just have the shop weld on the c4 end
i had the stock shaft shortened to fit the 700r4

our trucks are so light that you can't get enough traction to twist one in half
unless you try to light em up with 1000lbs in the bed

the C4 is aluminum, but I'm sure they could supply a steel version... I never even thought of using a stock driveshaft! Although I'd hate to hack up the perfectly good original shortbed driveshaft I have.. (my longbed one is long gone).

I will say that the original is a cold-rolled and welded shaft meant for under 200HP...so I'd have to behave myself probably. And that is unlikely to happen.

It does fit though! I tested it out. The amount of time I'd have into cleaning this thing... may be prohibitive as well. But good call out.

[mr48chev]

This is the U Joint choices for an 88 C-4 Corvette.

They list the steel and aluminum driveshafts different but both use what amounts to a 1310 series U joint
https://www.danaaftermarket.com/spic...-time-commerce


A 74/77 Nova driveshaft is 52 inches center to center of U joints and should take the 1310 U Joint if what I am finding is right. How close does that come?

I've had to use combination joints a number of time and really am not a fan. They are comparatively expensive and can be hard to find on the road if you have one go bad.

Speedway sells a rather spendy 80 something bucks front yoke for a 700R4 in a Nova.

I'm thinking that you are going to have to swap ends on a driveshaft if you want to use a used one and go cheap.

[fauXGT]

I'm trying to remember my center to center measurement is. Motor/trans is out but I think 55" is what I wrote on the driveline before disassembly. But I re-configured the stock steering shaft and made custom engine mounts, so the length can be different.
And this is for the C4 350 C4 700R and re-using the C4 aluminum driveline.

[G&R's57GMC]

One thing to remember, wreaking yards tend to use forklifts to move vehicles and usually the driveshaft is the first thing bent or damaged .

So be sure to check for straightness and dings .

Glad you’re back at it .

[mr48chev]

That is a thing you absolutely have to do.

I went out and looked in my driveshaft stash this morning and it is pretty well depleted and I didn't have anything close. I thought I might find one and remember what it came out of. The one under my 48 probably comes real close as the 48 has a Nova rear end under it.

[MARTINSR]

My brother recently gave me the driveshaft from my first car that I bought when I was 16 a few months after I bought my truck. It was a 64 Nova SS.

I WILL be using it in my truck......unless it's too short.

Brian

[daveshilling]

Originally Posted by mr48chev

A 74/77 Nova driveshaft is 52 inches center to center of U joints and should take the 1310 U Joint if what I am finding is right. How close does that come?

Yeah the shop said starting with the 1310 rear and shortening the other side/adding the 27 spline yoke is ideal. I'd use the combo's if I absolutely had to, but I agree that just getting a spicer 1310 would be better that the 1355/1310.

My measurement is 54 13/16 from tip of the spline to the center of the rear u-joint... I think the yoke removes about 1.5", and sticks out 3/4", so that would give me roughly 52 9/16 ish joint to joint, with some wiggle room cause those are approximations. If I had a proper yoke that I knew I'd be using, that would make measurements more precise. The nova is close!

Of course the alternative is $500 and a fresh new shaft and no searching/waiting/figuring. And yes, that's about where prices are these days. Supply is short, everyone is waiting for parts, it seems...
Trying to be patient!!

[daveshilling]

a 78-88 G-Body is 52.5", 27 spline yoke, but needs a 1350 U joint so it would require a pesky converter...although I don't see myself on road trips needing to swap U-joints as a primary reason I cant get down the road.

Could be a u-joint swap away from installation, though!

[mr48chev]

If the length is right you can use a combination U joint to match driveshaft to pinion yoke or driveshaft to the transmission yoke. The only issue with that is that they are about twice as expensive as a regular U joint and aren't always stocked at parts houses. Those two things are the only issues with them though. I had one in the 48 for years and did have to hunt for one once when mine went out. It still beats spending a couple hundred bucks to have a driveshaft made.

[_Ogre]

a little part of physics lurking out there called critical speed and 1/2 critical speed.

someone has been dying to say that, since he read it on the internet
i speak enginerd, but i posted tried and true for many builds 🤦

[fauXGT]

Still waiting for 'light speed'.