8 3/4" into a '73 COUPLE MORE QUESTIONS

[73ChargerSE]

Tried searching, turned up nothing.  Just got a 2.94 open center section for my 8 3/4".  Question is do I need to shorten my driveshaft when going from an 8 1/4" and if so, how much?  Also, there were 2 U-joint sizes for an 8 3/4", right?  If the current one I have is a small yoke, can I just change the caps to make it a large yoke if my next center section requires that?

Thanks for your help!
Paul

[Ghoste]

No the yokes are different (after all if the cap needs to be a larger diameter to accomodate the larger joint, the cup it is mating to would have to be larger as well), but you can get adapter u-joints where each half is a different diameter.

[flyinlow]

My 73/319/904/8 1/4 Charger.  First thing I did was install a 8 3/4 out of a 71 RR. with Mopar HD springs.

8 3/4 came with a 7290 flange (large). Buddy had a carrier with a 7260 (small) flange. He swaped. Both 10 spline flanges.

Original 904 driveshaft worked for the 2 months I drove it before putting a 440 in the car. Then I got a new driveshaft and swaped my 7290 flange back on.

73-74 Charger usually have rubber isolated spring clamps. If your 8 3/4 did not come from a 73-74 b body you will need a shock mounting plate for the non isolated style.

[73 charger]

yes...you need the 7290 yoke....mancing racing has what you need!  I upgraded from 8 1/4 to Dana from Drive Train specialists (DTS).  They also built me a new drive shaft with the heavy duty yoke/universal joint!

[RD]

8 1/4" to 8 3/4"  you can use the same driveshaft.. there is a slight length difference, but it can be compensated in the tailshaft housing of the transmission with no issues.

if you require a combination u-joint, it is a Precision 347 u joint.  that is a 7260/7290 combination to work with your smaller yoke and larger yoke size.  7290's are the preferred size in racing etc, but is not needed if you are driving on the street.  with 2.94's i dont think you are going to be a big time racer, so either yoke size will work fine dependent on how much power you are putting out from your engine.

[73ChargerSE]

The 2.94's are just until the fellow I bought my '64 from gets the 3.23 Sure-Grip center to me.  Did 8 1/4's have the big or small U-joint?

[RD]

The 2.94's are just until the fellow I bought my '64 from gets the 3.23 Sure-Grip center to me.  Did 8 1/4's have the big or small U-joint?

small

[73ChargerSE]

A couple more questions before I put the rear in this weekend.

-Can I use the same brake hoses and more importantly lines from my 8 1/4" or will I need to bend new ones up?  My brake hose has been replaced in the last couple of years. 

-I'm fabricating a metal bushing to fill the isolator hole to install SS leaf springs to avoid cutting and welding perches (rear has been powder coated).  How much longer of shocks do I need, or will I have to measure?

-Going with the SS leaf springs, do I need a different shock mounting bracket because I am eliminating the isolators?  My rear is from a '73 car.

Anything else I should know?

[73 charger]

I went with American Racing shock support towers.