69 f-body regaining ground clearance...

[gto406]

Hi all!

Ok searching on the suspension forum and the stickies and did not find a topic near to my issue/question.

Application: ‘69 Firebird
400 poncho w/iron heads & aftermarket a/c
Tires f: 225/45-R17 r: 245/45-R17
Stock interior.
Front susp: tubular a-arms (eBay cheapies) w/UMI ball joints (top and bottom), Comp-Engineering shocks, all new tie-rod, pitman (p/s), center-link, Ride-tech 500# coil springs (from street grip kit).
Rear susp: stock leaf spring w/Cal-tracs, Comp-Engineering shocks.

Car had a great ride height once assembled but has settled (according to my builder) - to the point that exhaust now scraping. What are my options to regain ride height?

Thoughts:
- switch to coil-over shock/spring setup
- spring isolators
- switch out my ridetech coil springs?

Any guidance appreciated! I can ask him to measure ride height (at the rockers). Couple of pics of the car. Hoping to maintain a decent stance - car will be street driven only - with some spirited driving (when opportunity available)

[dhutton]

These 1/2” coil spring spacers will raise the front 1”.

https://www.summitracing.com/parts/gls-1103

You will be going down the rabbit hole if you use conversion coilovers. The spacers are effective and cost a lot less....

Also available in 3/8” for a 3/4” lift.

Don

[gto406]

These 1/2” coil spring spacers will raise the front 1”.

https://www.summitracing.com/parts/gls-1103

You will be going down the rabbit hole if you use conversion coilovers. The spacers are effective and cost a lot less....

Also available in 3/8” for a 3/4” lift.

Don

Thank you Don!!

[gto406]

Thank you Don!!

Quick question Don - how does a 1/2” spacer give me a full 1” lift? Curious to understand.

Thanks again!
Brian.

[dhutton]

Quick question Don - how does a 1/2” spacer give me a full 1” lift? Curious to understand.

Thanks again!
Brian.

It’s because the spring only moves a half inch when the wheel moves an inch. The correct term is motion ratio if my memory serves me. Lots of good explanations if you google it.

Don

[gto406]

It’s because the spring only moves a half inch when the wheel moves an inch. The correct term is motion ratio if my memory serves me. Lots of good explanations if you google it.

Don

Thank you Don!

[gto406]

Thank you Don!

One other quick Q. How can I lift the rear end? Does the cal-trac give me some ability to raise rear bit? Or would I have to do something with the rear leaf springs?

BR/Brian.

[dhutton]

One other quick Q. How can I lift the rear end? Does the cal-trac give me some ability to raise rear bit? Or would I have to do something with the rear leaf springs?

BR/Brian.

Not much you can do there other than re-arching your leafs or new leafs or maybe add a leaf. It’s been a while since I’ve messed with leafs.

Don

[gto406]

Not much you can do there other than re-arching your leafs or new leafs or maybe add a leaf. It’s been a while since I’ve messed with leafs.

Don

Gotcha, thanks again. 🤟🏼

[XLexusTech]

Are you dying for HP or drivability? If you are with OK with a minor HP loss as in less then 10 HP.. ... shorty headers and tuck that exhaust up way higher so its no longer lower then that frame.. then your are all set..

[dhutton]

Are you dying for HP or drivability? If you are with OK with a minor HP loss as in less then 10 HP.. ... shorty headers and tuck that exhaust up way higher so its no longer lower then that frame.. then your are all set..

Agree 100%.

Don

[gto406]

Agree 100%.

Don

That is an option. I just put performance CATs on it, but run a nice/compact Hedman header. I noticed Sanderson sells a shorty header that might work (fits 69 Firebird) w/Pontiac V8. A review of Sanderson (Summit) noted he had to tweak on his steering box to get it to fit. So need to find out more. Hedman only makes a shorty for 64-72 a-body and 2nd Gen Birds (70-1/2 up).

The f-body engine bay fills up quickly!!

I am getting the car back, so may try it out as-is for a bit (including front: 1/2” spacer on coils, rear: remove lowering block installed on leafs). If after driving I am still having issues I will have him swap them for Sanderson. Car is in ‘working out the bugs phase’ as it was just completed.

Thanks gentlemen!
BR/Brian.

[gto406]

Are you dying for HP or drivability? If you are with OK with a minor HP loss as in less then 10 HP.. ... shorty headers and tuck that exhaust up way higher so its no longer lower then that frame.. then your are all set..

Thanks! I gotta get under it to see how the install of the exhaust went. I like the Hedman headers so my hope is I can tuck it up a bit tighter to the floor. If not have to find out if anyone even makes shorties for the 69 Bird/Pontiac engine combo!

[BMR Sales]

I think your main issue would be the Cheapie A-Arms - Chinesium Arms typically have a Drop Spring Pocket which will lower the car significantly

[gto406]

I think your main issue would be the Cheapie A-Arms - Chinesium Arms typically have a Drop Spring Pocket which will lower the car significantly

Yes I think you are correct. I am running a BMR x-member for the 700-R4 - do you guys have a tubular upper/lower setup (with good ball joints) I could replace the Chinese carpola arms with?

I have the comp-eng drag shocks and have not swapped out to an alternative shock setup. Coils are ridetech.

[dhutton]

Hmm, coil spring spacers or buy all new control arms. Decisions, decisions...

Don

[68Formula]

If the header flange is the low point, you could cut them off and use band clamps.

https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds

[gto406]

Hmm, coil spring spacers or buy all new control arms. Decisions, decisions...

Don

Hi Don, spacers are already in. I am looking at it thinking it still may below,

I will take some pics and post them so you can see the revised ride height.

Thanks!
BR/Brian.

[mean buzzen half dozen]

You can usually cut the the headers a bit to tuck them up close to the floor board.
Usually they hang down too low, and there is usually room to move them up.

[gto406]

If the header flange is the low point, you could cut them off and use band clamps.

https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds

Would a band clamp work between header and exhaust pipe? I have never seen that approach before. I did find these:
https://holohanshotrods.com/product/...imate-headers/

Any additional information you can share is greatly appreciated.

BR/Brian.