Firebird suspension update - Lateral-g Forums

Warpath Pontiac · #1 03-31-2010, 10:20 AM

I am going to be ordering all the parts to rebuild and update the front suspension on my '69 Firebird this weekend and I just wanted to make sure i'm headed in the right direction.

-I'm going to reuse the factory control arms and get polyurethane bushings and new ball joints.
-1-1/8" Hotchkis front sway bar
-Hotchkis subframe connectors
-Hotchkis SBC front springs (or would the big block springs be better for an A/C equipped car?)

and any opinions on shocks? I was thinking some KYB GR2s, but I really have no idea what to do when it comes to shocks.

**scherp69** · #2 03-31-2010, 11:28 AM

The Hotchkis stuff is good. I don't think you'll get a good response about KYB. Here's a thread from pro-touring.com where they talk about KYB shocks: http://www.pro-touring.com/forum/showthread.php?t=66695 Give Frank a call, he'll hook you up with the parts you need. He's ProdigyCustoms on that thread and his phone number is listed in his signature.

ProdigyCustoms · #3 03-31-2010, 11:40 AM

Pontiacs are about the weight of a small Chevy.

dhutton · #4 03-31-2010, 11:53 AM

Polyurethane bushings are not too popular here because they tend to bind. Most guys try to use Delrin bushings as near as I can tell.

Don

Warpath Pontiac · #5 03-31-2010, 12:56 PM

Wouldnt Delrin bushings mean I would have to jump to Tubular control arms?

I'm just trying to do a big bang for the buck front suspension upgrade that will make my 'bird handle better than it currently does. Would I see that big of a difference with delrin bushings in a car that will see mostly street use and some autocross down the road? And I dont mind spending the extra money, but would tubular control arms with delrin bushings be that noticeable of an upgrade? Also, I hate the phrase "While your at it", but would it be worth it to do the Guildstrand mod while I have the suspension torn apart?

I'll give Frank a call this afternoon. I'm sure he can point me in the right direction.

70rs · #6 03-31-2010, 03:07 PM

It seems to me that the best "bang for your buck" is to do a quality rebuild of your existing components. Add to that good quality shocks, springs and a good alignment and you will be amazed at what a difference it will make. Also a good steering box, very important. (don't forget the rag joint and subframe bushings, all of it makes a difference)

I have no experience with Delrin bushings yet, but since you stated you will be driving on the street most of the time I wanted to tell you I have read and been told that the Delrin bushings DO transmit A LOT more harshness from the road. If you want to keep your ride quality good there MAY be a better choice.
I am NOT an expert on this. Just my .02.

Good luck with what ever you decide.

Hotchkis · #7 04-13-2010, 08:44 AM

Quote:

Originally Posted by Warpath Pontiac

I am going to be ordering all the parts to rebuild and update the front suspension on my '69 Firebird this weekend and I just wanted to make sure i'm headed in the right direction.

-I'm going to reuse the factory control arms and get polyurethane bushings and new ball joints.
-1-1/8" Hotchkis front sway bar
-Hotchkis subframe connectors
-Hotchkis SBC front springs (or would the big block springs be better for an A/C equipped car?)

and any opinions on shocks? I was thinking some KYB GR2s, but I really have no idea what to do when it comes to shocks.

The build plan looks solid, and you'll be happy with the SBC springs, the Pontiac 350 and the stock iron Chevy 350 are similar in weight. If you want to go a little lower, the 3" spring works well. What is your current height on stock springs from the center of the wheel well opening to the ground? One thing people don't think about is 35 year old cars often have settled several inches over the years, so a 1.5" drop spring actually doesn't lower the car much if at all.

As for shocks, if you can swing it spend a few extra dollars and go for a true high-quality high-performance shock. You'll be glad you did. Our HPS1000 is made in Germany by Bilstein and valved to our specs, so its a great choice, but no matter which way you go avoid the over the counter auto parts store stuff.

Sounds like a really fun build, and '69 Firebirds are really cool looking cars you don't see as often. Post pics as you go forward with the project!

Josh69 · #8 04-13-2010, 09:48 AM

I used Hotchkis 2" drop BBC springs on my bird with iron heads because my research showed the Pontiac engine weighs around 650lbs, a BBC is 685(Mark IV) and a typical SBC is 575, so it's between the two, and I wanted the firmer rate. Now that they are on, the ride is nice, but they aren't quite low enough for me. I have 2" drop DSE leafs in the back and it has a fairly level stance with just a slight rake. I switched to aluminum heads and am adding A/C, so they'll probably end up about the same. My shocks are Koni's, which I personally prefer. Every Bilstein I have used has been harsh though I haven't tried the Hotchkis valved version. Even with these BBC springs, my ride is very compliant and it's never harsh. I have Global West Del-a-lum bushings in stock lca's, and same in Speedtech uca's. I also have the Hotchkis 1-1/8" sway bar. I have solid GW bushings and subframe connectors.

Josh69 · #9 04-13-2010, 09:48 AM

Quote:

Originally Posted by Hotchkis

The build plan looks solid, and you'll be happy with the SBC springs, the Pontiac 350 and the stock iron Chevy 350 are similar in weight. If you want to go a little lower, the 3" spring works well. What is your current height on stock springs from the center of the wheel well opening to the ground? One thing people don't think about is 35 year old cars often have settled several inches over the years, so a 1.5" drop spring actually doesn't lower the car much if at all.

As for shocks, if you can swing it spend a few extra dollars and go for a true high-quality high-performance shock. You'll be glad you did. Our HPS1000 is made in Germany by Bilstein and valved to our specs, so its a great choice, but no matter which way you go avoid the over the counter auto parts store stuff.

Sounds like a really fun build, and '69 Firebirds are really cool looking cars you don't see as often. Post pics as you go forward with the project!

How much lower would a SBC spring ride than the BBC spring and what is the spring rate differences? Is the 3" drop spring available for the SBC and BBC and what are the respective rates?

Thanks in advance for any clarification!

Warpath Pontiac · #10 04-13-2010, 07:29 PM

Im actually going with the Hotchkis valved bilsteins all the way around, along with springs, sway bar, and tubular uppers so I can do the guildstrand mod without cutting anything up. I ended up spending a little more than I originally planned, but I have a feeling I will end up with a really solid car.

And I went with the 2" SBC drop springs. I still have the factory springs in right now and if I can net around 1" to 1/2" drop I think my stance would be perfect.

One thing is certain, once everything is on the car and I get it aligned, i'm going to try and go through a couple tanks of gas driving around.