I have purchased a set or the Toms Upper Control arms, and I’m looking for installation tips. I found a picture online of one that looks complete, but I am mostly concerned about how the puter end is mounted. In the photo, it shows a plate welded over where the leaf spring bolt is dropped through. To me, that metal seems so thin to be welding a plate to.

If anyone can help guide me through this install it would be greatly appreciated!

Completed photo I found online.

Outer end of control arm

Where it looks like a plate is welded


Included instructions

 

Below is the description of what you bought from the catalog. Note it says OUR Trailing Arm not the stock trailing arm. You may want to contact them.

N.H.R.A. Approved! You go 10.99 & faster, you use these! We've designed our upper control arms to match the half-shaft angle. The upper plate is sandwiched in between the rear cover and cross member. The arm go's over and connects to our trailing arm utilizes 1/2" Heim ends, threaded arms for adjustments. Also includes half-shaft safety loops which can be bolted or welded in place (welded is preferred). They are 2 pieces for easy half-shaft removal. Part #V-UCR Price $640

 

I would contact Tom's and get recommendations.

If you insist on doing this yourself I would deal with a good chassis shop.
I do not know how you would add that heim joint bracket to a the rear of a stock sheet-metal trailing arm. Perhaps a box design that fits around the end, and can get welded on.

I do know enough about suspension geometry that you must get both the upper and the lower strut rods completely parallel, and also parallel with the halfshafts. If you do not the rear suspension will bind when it moves up and down, since you now have three rigid links. Test it with no springs and make sure there is no binding! You can see where they lowered the lower inner strut rod mount from stock, roughly 1" to 1-1/2" to achieve the parallel strut rods. Check with Tom's or a chassis shop on advice from here.


All three red shafts must be parallel. On one of these setups (Drag Vette?) they recommended removing the inner axle stub c-clips to let the axles float slightly to prevent any possible binding, in case your positioning is not perfect.
All thee of the joints must line up vertically (yellow)
The inner lower strut rod mount is lowered and custom fabricated until the above apply. (green)
The yellow lines are not parallel (different length shafts) so you will still have some camber gain when it squats, but it should be much less than before due to the parallel shafts.

It is definately not a bolt-on mod. Good luck!
I remember your wheels up drag launches. You need these!

 

The inner end of the new lateral control arm moves in a slot so it is not completely rigid.

 

the rods float in the slotted bracket. The top bracket bolts in and the rod outer ends mates to Tom's offset arms with welded bracket. If Tom's arms are not used then a bracket has to be fabricated and welded

 

Here are the arms

2- LH Toms offset arms with upper link bracket

 

I see exactly what you mean now! I see the part on Toms site, but it says it requires a 2.5”shorter spring. I have just received my 420lb composite spring, in the stock length. Is this going to be an issue? Is there a way around this, or do I need to find a new spring now as well.

 

We had to add a leaf as there was too much play in it. Remember shock loading and dead hook break parts.