The Money Pit

From what I found,most GM universal joints were 1310 series.Most aftermarket yokes are 1350.They're not the same size of course,but is it really nessesary to put 1350 joints on a street driven Vette with just a tad over 500hp? Or can I save a bundle,and just rework my stock driveshaft and install a th400 yoke.

This is all due to me swapping the 700r4 out,and installing a th400.I chose to loose the OD gear and go back to the three speed for strength and durability,as the past three trannies could not do the job.Going full manual reverse VB on this one.

Twin_Turbo

1330 should do. Most cars came w/ 1310s but they are on the small side IMO. 1330s have 1350 sized bodies w/ 1310 sized trunions.

Your diff uses a 1310 pinion yoke, so you'd either have to get a 1350 or 1330 yoke for it (dennys driveshafts should have them) otherwise going to a 1350 shaft is pretty useless if you keep the small one on the pinion side..IMO

gkull

I never had a problem with the U-joints behind my custom shortened drive shaft. I think what saves them is a setup which is nearly straight and the fact that they are not subjected to like in my case 4.11 TQ multiplier rear end like the half shaft have to endure.

For the cost of building up a 400 you could build up a 700R4. Once I spent the money and got the high HP 700 it never had a problem again. The 700 can also be bought with a full manual reverse valve body and transbrake. Even with a racing pump the 700 uses less hp than a TH400

The Keisler kit drive shaft is 1330 equiped. I sent my 1350 stuff to TT

Mako72

Keisler also now has an optional driveshaft with a smaller non-zerk 1310 ujoint at the transmission end for those with tunnel clearance issues.

TimAT

Found this info at http://www.dana.com/

Tried to paste the chart, but it was not readable. So the link is here anyway. It has the sizes, diameters and strength all listed.

Hope this helps..

GrandSportC3

I'd definetely upgrade.. 500 HP seems too much for 1310 u-joints IF larger or sticky tires are used. If you upgrade the u-joints, upgrade to solid 1350 series.. 1330's should be ok, but 1350's are basically bulletproof as driveshaft u-joints (half shafts are another story)..

I had those teeny tiny u-joints on my '68 as it was a 4-speed car... I went with 1350 series for the driveshaft and with 1480 series for the half shafts.. The 1480's on the half shaft would be overkill with only 500 HP though...

The Money Pit

The drive shaft I have is a 2 1/2" stock shaft. Will a 3" shaft clear the tunnel? I assume I'd need a larger shaft to install larger yokes and u-joints.


On a side note...been working on the website. Can some of you check it out and let me know if you have trouble opening it from the link in my sig?

GrandSportC3

It all depends on how centered your tunnel is. Mine is off center but my 3 inch chromoly driveshaft still has enough clearance...
My shaft is a PST (Precicion Shaft Technology) chromoly driveshaft and I got it through Van Steel.. It's lighter and stronger than steel driveshafts....

P.S. your site works fine when clicking the link in your sig!

rj8806

You wouldn't need a larger driveshaft to install a larger u-joint. The weld yokes will need to be changed. As for a 3" tube in a vette.... You will run into some tunnel clearance issues for sure.
A 1310 u-joint is supposed to be good for 400ft/lbs of continuous torque and 800ft/lbs of short duration torque. The 1330 is good for 550 and 1000 respectively. The 1350 is good for 680 and 1240 respectively. Hopes this helps.

Richard
Tech Support
Keisler Engineering

GrandSportC3

I wonder what size u-joints those 7 second outlaw cars are using on their driveshafts.. Some of them have more than 1240 ft/lbs of torque... I wonder if they are using 1480 series???

The clearance should not be a main issue and can be easily determined.. Just check your current clearance and see if you have over 1/4 inch clearance. If you can get your fingers around your current 2 1/2 inch shaft anythere along the shaft, the 3 inch shaft will clear.