69 GTX suspension restoration

[Kevin Bisgrove]

Looking for overall input on my suspension and what I should do.
Going for stock restoration but changing to disc brakes in the front but staying manual.

Planning on reusing upper and lower control arms, sway bar, center link, strut rods and torsion bars, K-Member.

Questions:
- should I replace Tie Rod ends and sleeves? Just ends? Or use existing with new boots? Assuming replace only the ends.
- should I replace the idler arm or just new bushings and seals? Seems ok.
- same with Pitman arm? Assuming replace.
- proforge ball joints and bushings?
- what sway bar bushings should I get? Assuming I should replace?
- what strut rod and torsion bar bushings should I get? Assuming I'd replace both?
- changing to disc fronts, should I replace spindles or try using original (I've looked at Dr Diff)
- do I need to reinforce my LCAs? Assuming not too.
- should I get everything blasted or just cleanup and evaporust?

I already know most of the stock original finishes for all the pieces from research here on FBBO!

Thanks for any input.

 

[moparedtn]

 

[hunt2elk]

I've been using as much Proforged suspension stuff as possible, and have been happy. One thing they don't make yet is the offset upper control arm bushings if you are going that route. Moog has been getting a bad rap lately for poorer quality than it used to have. You will need new spindles if using Dr Diff's disc conversion. There are some kits that do use the factory drum spindles with their disc conversions however. I have also been upgrading the tie rods and adjusters to the bigger 11/16" C-body parts. PST sells stiffening plates for your lower control arms that work well also.

 

[yella71]

Are those tie rods worn out? what about the pitman? or idler? old OE parts that are NOT worn out are better that NEW chinneese parts any day. replace whats worn out and keep the rest. as far as clean and refinish do what you want. Is this gonna be a 100 point show car? or you just want a reliable ride. Replacing parts just to replace parts makes no sense to me. If they're good they're good Thats my take

 

[Hilljack68]

I replaced tie rod ends (Moog); bushings were all replaced (mostly with poly); I cleaned and painted any original steel parts (sleeves, arms, etc). I did, however, stiffen things up with bigger torsion bars... I went with 1.03" from PST.
Out back I kept everything stock. New leaf spring bushings, and I had the leaves re-arched. Again, the steel (leaf mounts, etc) got cleaned and painted.
I too upgraded to front discs from Dr. Diff. I left them manual, but replaced all the lines and the MC. And, like Elk said, you will need Dr. Diff's spindles.

 

[Kevin Bisgrove]

View attachment 994518

Definitely been seeing mixed opinions on Moog. A buddy went Moog and was happy with everything.

 

[Kevin Bisgrove]

I've been using as much Proforged suspension stuff as possible, and have been happy. One thing they don't make yet is the offset upper control arm bushings if you are going that route. Moog has been getting a bad rap lately for poorer quality than it used to have. You will need new spindles if using Dr Diff's disc conversion. There are some kits that do use the factory drum spindles with their disc conversions however. I have also been upgrading the tie rods and adjusters to the bigger 11/16" C-body parts. PST sells stiffening plates for your lower control arms that work well also.

What do the larger tie rods do for the ride?
Do you think I need the stiffeners?
I'll look at my options with the spindles before I do anything with them.

 

[Kevin Bisgrove]

Are those tie rods worn out? what about the pitman? or idler? old OE parts that are NOT worn out are better that NEW chinneese parts any day. replace whats worn out and keep the rest. as far as clean and refinish do what you want. Is this gonna be a 100 point show car? or you just want a reliable ride. Replacing parts just to replace parts makes no sense to me. If they're good they're good Thats my take

Not 100% sure how to tell if the tie rods, idler arm and Pitman are still good...
The idler arm seems fine, no slop and can't move it at all.
Pitman arm has torn boots and I can move the joint by hand.
Likewise with the tie rods.
Going for a top notch resto and not looking to replace parts just to say I did!

 

[Kevin Bisgrove]

I replaced tie rod ends (Moog); bushings were all replaced (mostly with poly); I cleaned and painted any original steel parts (sleeves, arms, etc). I did, however, stiffen things up with bigger torsion bars... I went with 1.03" from PST.
Out back I kept everything stock. New leaf spring bushings, and I had the leaves re-arched. Again, the steel (leaf mounts, etc) got cleaned and painted.
I too upgraded to front discs from Dr. Diff. I left them manual, but replaced all the lines and the MC. And, like Elk said, you will need Dr. Diff's spindles.

Thanks for this, I've heard about upgrading the torsion bars. What will that do for the ride? What about struts?

 

[Hilljack68]

I've heard about upgrading the torsion bars. What will that do for the ride?

If you change to a bigger engine, you'll definitely need bigger torsion bars. But even if you keep your present engine, changing to a larger bar will make the front end have a "stiffer" ride, having less body roll in turns and less bottoming out. The thicker the bar, the less "twisting" of the bars, and less movement of your LCAs in turns.

 

[moes]

using C body tie rod end to replace the stock B body ones is a good upgrade if you are using larger front tires on your car. C body tie rod ends has a 11/16 inch diameter shank which is TWICE as rigid as the B body tie rod 's 9/16 inch diameter shank. I do it on all my B body cars I've had.

 

[Kevin Bisgrove]

If you change to a bigger engine, you'll definitely need bigger torsion bars. But even if you keep your present engine, changing to a larger bar will make the front end have a "stiffer" ride, having less body roll in turns and less bottoming out. The thicker the bar, the less "twisting" of the bars, and less movement of your LCAs in turns.

I'm keeping the original motor and power but sounds like going to bigger bars would tighten the ride feel. Looking for a nice cruiser that rides great so this probably is worth doing.

 

[Kevin Bisgrove]

using C body tie rod end to replace the stock B body ones is a good upgrade if you are using larger tires on your car. C body tie rod ends has a 11/16 inch diameter shank which is TWICE as rigid as the B body tie rod 's 9/16 inch diameter shank. I do it on all my B body cars.

So they are a direct swap? What did my 69gtx? 69 c body?

 

[hunt2elk]

What do the larger tie rods do for the ride?
Do you think I need the stiffeners?
I'll look at my options with the spindles before I do anything with them.

Larger tie rods are much stronger than the 9/16" ones that came in the car and are a direct swap. The stiffening plates remove any sloppiness in the lower control arms, and are cheap and easy to install. I also use PST 1.03: torsion bars in all my cars.

 

[moes]

So they are a direct swap? What did my 69gtx? 69 c body?

yes they will bolt right up. You will have to buy the C body 11/16 inch adjusters to, I use aftermarket billet aluminium type adjusters, they are stronger then the factory type C body adjusters

 

[Kevin Bisgrove]

Larger tie rods are much stronger than the 9/16" ones that came in the car and are a direct swap. The stiffening plates remove any sloppiness in the lower control arms, and are cheap and easy to install. I also use PST 1.03: torsion bars in all my cars.

Great info thanks. I'll look to go bigger tie rods and torsion bars with the stiffening plates.
What are your thoughts on struts? Using existing it upgrade as well?

 

[Kevin Bisgrove]

Great info thanks. I'll look to go bigger tie rods and torsion bars with the stiffening plates.
What are your thoughts on struts? Using existing it upgrade as well?

Thoughts on sway bar too? Stock or thicker as well?

 

[hunt2elk]

Great info thanks. I'll look to go bigger tie rods and torsion bars with the stiffening plates.
What are your thoughts on struts? Using existing it upgrade as well?

I am not a fan of the adjustable struts, or the ones with a heim joint. Last 2 cars I have used heavy duty solid struts from Mancini. They are massive compared to the originals. Nice quality and are made by QA1. I always use the factory front sway bars and have no complaints with them. Might want to ask @Kern Dog his opinion on those, as I believe he has done some experimenting with larger aftermarket ones.

 

[Rockland71GTX]

Just remember that your suspension is a system. 'Stiffness' means two different things when used here;
First is taking the slop out of the suspension by using components that deflect less than stock such as polyurethane bushings and the thicker tie rods/sleeves, etc. These upgrades will give you greater steering feel and feedback.
Second is increasing the spring rate and or sway bar thickness. In these cases you also have to consider the WHOLE system! Too much stiffness at the front with thicker torsion and sway bars will increase the tendency to understeer. To correct this you would have to add a rear sway bar. I think going to a 1.03" torsion with a stock sway bar is OK but adding a thicker sway bar would require further upgrades.
Here is a sample order for Rockauto that I would do. It includes fast-ratio Pitman and Idler arms that will give you better steering response.

I would replace everything in one shot. I don't know if you're handling the labor or paying someone else to do it but doing a job once and being done with it is the way to go!

 

[Kern Dog]

A general rule is that the end of the car that has the highest overall spring rate will lose traction first. Think about that for a moment.
It is true that you should look at the front and rear suspension as a system that needs to work together.
If your goal is to just simply improve the road holding capability, better tires and shocks go a long way if the bushings, ball joints and tie rod ends are all in good condition.
I went further. Mine is a 1970 but is essentially the same as yours.
I added my own lower control arm stiffening plates. Nobody made them 18 years ago when I heard of the idea. This is unnecessary if you are using a small original sway bar. My front sway bar is a modified front bar from a 2wd 73-87 Chevy 1 ton truck. It measures 1 1/4". Add to this the 1.15" torsion bars, the front is stiff but not too much.
The rear is pretty simple. 440 4 speed/Hemi leaf springs (5 1/2 leafs) and a 3/4" sway bar. Bilstein RCD shocks.
No fancy strut rods, no urethane bushings except at the strut rods either. I do have Moog K 7103 offset upper control arm bushings to allow for more caster. It rides nice, steers great, corners really good and is fun to drive.