1971-1974 Javelin U-Joints

I have some nasty vibration at around 55 MPH in the Jav and the driveshaft wiggles a bit at the front. I'm going to get new u-joints and see if I can either get the existing driveshaft balanced or get a new one from Tom Woods.

I've always been a fan of Spicer u-joints, but I'm having some difficulty figuring out the correct ones. Summit and JEGS don't list them at all and Amazon says the Spicer 5-153X "works" for my car. Does anyone know the correct Spicer u-joint part numbers for the front and rear? If Spicer isn't an option, what would you recommend? Unless there's no other option, I'd prefer not to use parts store stuff. The car will eventually be putting out lots of power so I need strong parts.

IF the front joint is loose enough for the driveshaft to wiggle that's the issue, not balance. I'd try the u-joint and only look for another culprit if that doesn't fix it -- but I bet it does. 

I like the non greaseable spicer ujoints, i put a 1350 yoke and spicer ujoint on the model 20 in my jav. I would reach out to a local 4x4 shop they may stock what you are looking for.

Im not saying you need to upgrade to a larger ujoint, just saying a local 4x4 shop might stock the solid spicer joints. The napa stuff will hold up fine im sure.

We have a local 4x4 shop that has been around forever, they stocked all the seals, timken bearings etc... stuff that has been collecting dust because no one builds a model 20 anymore LOL. worked out well when I put mine together.