I have reached the part of my 1968 Javelin project that I need help with.  My Javelin is an SST with a 290 4bbl and a 700r4 trans.  My next stage is to update/improve the rear suspension and differential.  Basically I want to move up to a limited slip diff. with 3:54 or 3:73 gears and some sort of traction aids(bars or ?).  I am looking forward to seeing what Car Craft does with their AMC project but would also like to know what others out there have done to get the power to the pavement?  I have Gabriel Hi Jackers for shocks but am wide open for any other suggestions.  The following stage to the rearend will be a 401 that I will be trying to get 4-500hp out of so I really need to make sure the rear axle is firmly planted.  Thanks in advance for any help you'all can give.

Michael Hayes

I'm assuming you have a Model 20 rear in your 68.  Im my 68 amx when rebuliding the rear the weakest point is the 2 piece axles.  I had 1 piece axles put in (moser makes these), an Eaton Posi with 4.10 gears. and was basicly told that the limit of this should be no more than 500hp which i cant see mine makeing this at the wheels.

the other items i added were KYB gas shocks, urathane bushings and raised the rear about 3 inches by having the rear leafs rebuilt and re-arched. I added Lakewood universal traction bars and with this setup the problem is the AMX is light in the rear or I need better tires.  I don't get any axle hop and the car consistantly lays down a nice even patch of rubber in my driveway test area.. 

Thanks for replying Sean.  I will be using air shocks to gain heighth in the rear as needed.  Do you have any trouble with the traction bars on ground clearance issues?  Thanks again!   

no problem with the traction bars but i have the rubbers in the front almost touching the springs so they hit the springs quickly.  I haven't had any issues with the speedbumps in our local home depot.     

I want to know what is needed to get the 700R4 trans into the amc? Im looking for a tranny swap and an overdrive would be nice with my 4.10 gears..?  Any info on your setup would be helpfull.  

Checkout "performanceamstyle.com" to find the adapters.  Email them for more info if the site does not show any for your application.  Mine was for the 290 - 390 engines and worked great.  My garage(Frisco Automotive in Frisco Texas) had to make a modified rear transmission mount and shorten the drive shaft about an inch.  I bought a Hurst 700r4 shifter and it was adapted right over the existing shifter slot.  It makes a world of difference.  Wish I had a tach on this before I installed the trans.  The 290 loafs along in 4th.  First gear is somewhat useless as it spins the right rear instantly.  It chirps the rr even on the 2nd to 3rd shift.  This is one change that is well worth it.  

The guy at Performance American Style's name is Randy Guynn.  He's a pretty nice guy and helped me and my shop a lot with the 700r4 swap.  One other thought if you have a 727 or t400 already the Gear vendors overdrive unit might be a good alternative also.  If you have the Borg Warner I'd definitely go with the swap.  Even the AMC book "Performance American Style" tells you to only use the 727 for performance uses.  Good luck with your machine!