Suspension Rebuild Suggestions

[71383bee]

Hello All.  I'm just looking of some advice on doing a front nd rear suspension rebuild for my stock 318 convertible.  The car is a a 1970 318 convertible with the standard suspension.  Its just a road cruiser so the focus is reliability and comfort rather than performance.  For these reasons i would like to stick with rubber OE style replacements unless there are strong considerations otherwise.  The car does not have sway bars. 

I've used ESPO for the rear springs and plan on that for the rear.  My question is whether or not to go with the 1" over arch on the stock springs.  Or is it better to go R/T style springs?

For the front I am considering ESPO, Just Suspension or PST for a super rebuild kit with the cam bolts, bumpers, and full tie rods.  Question is if its worth while to go tubular upper A Arms or adjustable strut rods or not.  Also like opinion on who to go with.

Torsion bars are the small ones and original.  is it worth upgrading or do the originals hold up well?

Shocks are the last big item.  I DO NOT want KYB's but am open to a better quality shock but again this is a cruiser not a road racer.  Any suggestions here would be greatly appreciated. 

[Rich G.]

I've rebuilt all my E bodies with stock stuff because I just cruise with them and it's good enough for what I want and they drive pretty good for what it is. Just use quality parts. If you plan on beating it or doing auto cross then you'll need some serious upgrades.

[HP2]

Rubber is fine for a cruiser. I wouldn't hesitate to use it.

Sway bars, I'd certainly suggest getting a front unit. Rear's are nice, but not totally necessary for simple cruiser.

I'm not a fan of lift springs, but many are. I'd say this depends on your tire diameters. If you have a taller tire in back, you already are going to get lift. If you tires are the same size all around, then a lift may potentially make the rears look small. I'd prefer to drop the nose a bit over lifting the rear, but a lot of personal choice and driving concerns around this selection. Flatter springs do handle better, but convertibles aren't corner burners to begin with. So you are aware, R/T style springs don't provide lift but do provide greater spring control against wrapping. If your 318 is backed by a 4 speed, this may help. With an automatic, may be no difference.

A full kit with all ball joints is highly desirable. If it comes with bumpers, great. Cam bolts, not needed unless they are part of the kit or yours are nasty. Tubular arms, maybe. This is contingent upon alignment and tires. Tubular arms give you more positive caster and negative camber and this alone will improve your car's handling with no other changes. However, if you use radials and have power steering, these benefits are realized. If you use bias plys or manual steering, the more aggressive alignments will increase effort and tire wear. Another option for sluightly more range of adjustment is to use offset rubber upper control arm bsuhings. These won't get as much alignment range as tubular arms, but are better than stock bushings.

Speaking of which, if you are using radials, DO NOT use the stock alignment specs. They are for bias ply tires.  Instead ask for custom specs; as much positive caster as possible, 0-.5 negative camber, 1/16" toe in.  Or if you shop needs a spec car, use '04 Mustang GT. They won't be able to hit it, but it does give them a target.

Torsion bars... IMO, these were undersprung from the factory. Stepped up rates improve cornering, reduce nose dive and reduce lift at speed. However, stepped up rates do require additional shock control.  I've found that Monroe gas charged shock offer good t-bar control up to about .96 diameter. After that, you would want to look at either specifically valved shock such as Bilstein or a single adjustable. Speaking of which, shocks will make the overall system feel better put together. Buy as much as you can afford here.

you didn't mention any uni-body stiffening efforts. I'd certainly recommend these with a drop top car. reducing body flex not only improves the way a car drives, it will also stop squeaks and rattles and allow doors and tops to all mesh together more consistently.

[Chryco Psycho]

I agree with HP2
I would go with bigger T bars , stay with the stock upper control arms , +1" for the rear springs if you prefer , I would add both front & rear sway bars . Stiffening the chassis is a good investment also .
For shocks I would use Bilstein , QA1 , But KYB are Junk .

[71383bee]

Thanks guys!

The car has power steering and I am using 225/70r14 cooper cobra tires on 14x6 road wheels.  I plan on going to the Goodyear FR70-14 reproduction tires which I believe are a bit smaller than the ones I'm running now. 

I would love a front sway bar but my lower control arms don't have the provisions for it.  Are there kits out there for this?  Or am I stuck trying to find a set of OE lowers?  Will 71+ B body ones work? 

For torsion bars who is best to source this?  ESPO does not have them.  I'm assuming I just want a stock style for an R/T which I believe is 0.96".

For rear springs I actually like the height it has now.  It seems slammed to the ground compared to my 73 Rallye but I don't feel I want to go too much higher.  I'll attach pictures of what it currently looks like. I admit the ass does look like its dragging a little but i was thinking the stock springs should recover some of that.  Just wondering if the additional inch will be too much. 

[7212Mopar]

Firm Feel or PST for torsion bars. You can weld tabs to your existing lower control arms which you need to loosen in order to install new torsion bars. Plan the work and replace other parts like bushings and ball joints at the same time while you are at it.

[Skdmark]

Good advice from Chrycho.

For the lower control arms you can buy the sway bar tabs and have them welded on when you are rebuilding the suspension.
I went with +1 inch rallye suspension springs on on my 318 Barracuda hardtop from Eaton Detroit and really like the height. It is actually pretty level and not tail high. I'm running single adjustable QA1 shocks all around too.

For torsion bars there are a couple options out there. PST, sway-away, firm feel, Mancini, Hotchkis etc.
0.96 would be the thinnest I would go with. I'm planning on 1.03 and might do 1.1

I would also consider having your power steering box rebuilt with either a Firm Feel stage 2 or 3. Then add the quick ratio pitman arm and a c-body idler arm.

[70vert]

I agree with the suggestion of Firm Feel, they will have all you need and can give great advice/recommendations. I upgraded my torsion bars to 1.06 (but I've got a heavier 440), and am using Bilstein from them also. I already had a front & rear sway bar but planning to upgrade from stock soon. And I'm pretty sure they can fix you up with mounting. I'm just a cruiser and it rides incredibly better.

I used poly-graphite bushing from PST, but actually wish I'd stuck with rubber. may change them out when I have time.

I actually went the other direction and wanted mine as low as possible so using a front spring hanger from Mancini (I think) that has 2 mounting holes. 1 is stock spec and the other is 1in lower.

Gorgeous car BTW 

[dodj]

1.02 bars, PST or firm feel.
Moog offset UCA bushings installed for caster. Tubular UCA's are too pricey in my opinion.
Moog rubber LCA bushings.
Moog strut rod bushings.
QA1 single adjustable shocks all four corners
Strut rods are fine. If you have some extra $$, buy QA1 or pst adjustable.
Rear springs is really up to your preference on rake. I have Mopar XHD rears and they are perfectly flat, which is perfect for me. I prefer better handling over mid '70's rake.
If you prefer the ass in the air look..go for it.
Don't align anything until you have finished with the rear springs and set your front height.

[71383bee]

Wow guys!  Thanks for the weatlh of info. 

I knew about firm feel and have used their boxes before but after checking their site I got to say I am very impressed. 

What got me on this path is that I swapped wheels form my 73 to the 70 this past weekend to see if I wanted to pursue getting a set of road wheels and my wife and I really prefer the road wheel over the rallye's.  The trouble came as i took it for a spin and I noticed something was hitting the suspension as i was turning with the "new" wheels. 

While swaping them back to the rallyes on the front I noticed that the "old" front tires are worn severely on the insides and a look at the suspension looks extremely worn and not well maintained.  I think the hitting came from the fact that the road wheels had weights on the inside rim and there were grease marks all over them and there was scuffing on the upper control arms at the ball joint.  I think if i get the wheel re balanced with weights on the outside rim it will work but felt that the clearance is awfully tight for a stock road wheel to hit the suspension.  I now want to get an alignment to correct the issue but am pretty sure they are going to tell me the whole suspension is shot.  As with all other things suspension requild was more on the long term list rather than immediate and it will curtail some plans for her.  Ohh well its not a bad problem in my opinion!  any improvement is worth the effort on these old girls.