Dart drive shaft

[orangecrush]

Want to get a head start - 72 Dart Swinger w/340/727/8.75. Any reason I shouldn't go ahead and have a driveshaft made to the factory measurement for 70 340 cars ( don't have it handy 48 or 49 inches ) ? Really like to have it ready to install. What possible variables could there be that may effect length and screw me up ? Does small vs large yokes make a difference in length ? I may have 7260 on front and adapter to 7290 on back . Only those that know for sure need reply - no "if it were mine ......" Should be pretty cut and dry answer (or cut and install, even better!) Thanks

 

[Dart Advantage]

I did this all back the '80s, in steps.
First was the 8.75 , and I had the original shaft shortened.
Then was the 727, and the original could not be re-shortened.
They did re-use the front yoke, but put the bigger Spicer yoke on the back end of the driveshaft and I have the "converter" u-joint in back.

There is also the 108" vs 111" wheelbase issue..
Just make sure you have specs for a shaft from a Dart, not a Duster or Demon.

Much more recently, I ran into this issue replacing the trunnion type drive shaft on my '65 GT.
I ordered a used shaft and it was too short. Must have been a '63 Val shaft or something.
Had a new one made, and this shop saved the rear yoke from the old shaft, so I have original style u joints on this car. On the front we put a Spicer 2-2-349 flange yoke to bolt to the '65 trans flange.

 

[orangecrush]

Yeah - I got the specs from a chart for 70 340/727/8 3/4 Dart Swinger - so I'm comfortable this will fit - my concern was the adpting the rear to large pinion and if this caused a variance in length but doubt it. Shaft is from a 318/904/ 7 1/4 rear (original combo before converting) so will need cut down, front will bolt up, back end will need the mods (?) , just want to drop it off and pick it up done right so I can powder coat - drive the car out of the garage on day of fire-up vs wait and measure, etc.

 

[cosgig]

There is no difference in the length of the 7260 vs. the 7290 or in the adaptive u joint that has the 7260 on one side and the 7290 on the other. I would feel comfortable going with the factory specs, the only thing I would advise is that you make sure the person doing the work knows where the factory measurements were taken from. I have had a number of driveshafts shortened by a 3 different companies in my area and they all figured the length differently. There is some room for error, but not much more than a couple of inches. The rear mods should be as easy as cutting off the old saddle and welding on the new saddle of your choosing, but I would also suggest trying to use the same size u joint front and back, preferably the 7290. Hope your man gets it right the first time, and you don't get the "shaft". Oops, sorry, that kinda just slipped out.Geof

 

[Small Block]

My fool proof way is as i do. I get it all istalled in car minus the shaft then load her up and take it to the shaft shop or have the guy come to my shop and we measure what is there less 1" for spline travel and then it's correct. No problems here. In the BB cars i use the 1350 yokes.

 

[Dons67Barracuda]

i just installed a 727 trans & 8.75 rear and i took a measurment and it worked the first time. install Yoke in trans tight measure from center of u-joint to center of u-joint on third member. once you have your measurement take off 1". and it will work perfect. this is what i did. just remember you must have car supported on the rear axle. as if it was on the ground.