Ridetech for 69 Firebird?

[jlwdvm]

My 69 Trans Am clone project is getting to the point where I have to start making decisions on rear end, wheels-tires, suspension, etc. I an finishing up installing a Chris Alliston 6-point roll bar. I already mini tubbed the car this winter. It has an 8.5" rear in it at the moment that will probably be changed out to something that can handle 500+ Pontiac horsepower. I'm thinking about a full ridetech front and rear suspension kit with coil-overs. I will be using a stock front sub frame. Questions are: Do I run a stock width rear if I want 335 tire; are there tire width limitations since the lower control arms bolt up where the stock leafs would on the rear end; what size of tire could I run without adding true-turn, does the narrowed frame rails affect the rear 4-link attachments? Any other input would be great!

[Josh@Ridetech]

The car already being mini tubbed will allow you to get that tire under there, but the stock width of the rear end is good. The backspacing of the wheel is the main thing that you need to take into consideration on the rear. On the front, you'll be able to run an 8" wheel. You'll also need to notch the AirBar bracket for the frame rails.

[Tim john---]

What are you using for a gas tank w/ the mini tubs ? I too have a 69 Firebird convertible and am at the gas tank phase, car is already mini tubbed. I want to keep a factory looking stock tank and am searcing for a source for a narrowed "stock" looking tank. Any advice ? Thank You.

Tim john---

[jlwdvm]

I think you only have to go to the narrowed tank if you want to run leafs with off-set shackles....an I wrong? My thoughts were that by the time I buy a narrowed tank, off-set shackles, new leafs, shocks, shock mounting bar, etc I could just buy a ridetech 4-link with everything and not need a new tank (I have a new stock tank already) and have better performing suspension for very little more money!

[Tim john---]

Thank You for responding, I have the DSE mini tubs installed already, was planning on using the factory original reaf leafs and already purchased the DSE offset shakles (beautiful piece of machining excellence). Trying to stay on budget is mighty difficult with these projects. My current plan is to narrow the original tank, convert it for the LS fuel injection, notch the tank corners for exhaust clearance and re-install. Where are you located ? Would love to see your car sometime for inspiration and ideas to carry over.

Tim john---

[jlwdvm]

I am located in eastern Iowa...not exactly a pro touring mecca. I purchased the Ride Tech stage 2 complete kit with coil overs, Tru Turn and Muscle Bars. I have the front sub out of the car at the moment. I have all the seams welded up and am getting it ready for paint. I installed a 6-point roll bar after I installed the wheel tubs. Wilwood 6-piston brakes are sitting on the shelf too. Next purchase will probably be a Ford 9". I need to start asking questions to Butler/Kaufmann about building a motor to use on the road course.

[marolf101x]

Where about in Eastern Iowa?
I'm originally from Moscow (30 miles east of Iowa City on I80).

[bret]

My 69 Trans Am clone project is getting to the point where I have to start making decisions on rear end, wheels-tires, suspension, etc. I an finishing up installing a Chris Alliston 6-point roll bar. I already mini tubbed the car this winter. It has an 8.5" rear in it at the moment that will probably be changed out to something that can handle 500+ Pontiac horsepower. I'm thinking about a full ridetech front and rear suspension kit with coil-overs. I will be using a stock front sub frame. Questions are: Do I run a stock width rear if I want 335 tire; are there tire width limitations since the lower control arms bolt up where the stock leafs would on the rear end; what size of tire could I run without adding true-turn, does the narrowed frame rails affect the rear 4-link attachments? Any other input would be great!

On the front:
If you are going to NOT use the Tru Turn system you will be limited to a 245mm tire on an 8" rim with a 4.75" backspace. If you use the complete Tru Turn system [an extra $650] then you can go up to a 275mm tire on a 10" rim with a 5.75 backspace. AND...you'll have much better overall frontend geometry by optimizing the bumpsteer.

On the rear:
There is one corner of the AirBar cradle bracket that must be rounded off because it overhangs the typical minitub by about 1/4". It'll take you about 20 seconds with a grinder. The lower AirBar control arms are offset to the inside by about 3/4" on each side so they will clear a 335mm rear tire. If you are buying/building both a new rearend and new rear wheels then you have lots of latitude of the width of each. BUT you must coordinate those dimensions. Start with the wheels, then get the rearend built to match the offset of the wheels.
OR...if you already have a rearend, then get the wheels built to work with the width of the rearend.
The constant in the equation will be the position of the outer fender lip and the inner wheeltub. Spend lots of time measureing.

[jlwdvm]

I will probably be running Vintage Wheel Works V40's with a sticky street tire, but haven't decided on 17 or 18" wheels. I am wondering if any massaging will have to be done to the front inner fender wells to get a 275 tire in there without too much rubbing.

I am just north of Davenport about 15 miles (Long Grove)...not too far from Moscow!

[bret]

I will probably be running Vintage Wheel Works V40's with a sticky street tire, but haven't decided on 17 or 18" wheels. I am wondering if any massaging will have to be done to the front inner fender wells to get a 275 tire in there without too much rubbing.

I am just north of Davenport about 15 miles (Long Grove)...not too far from Moscow!

If you use the Tru turn, a billet 17" wheel will work. A cast 17" wheel MIGHT work, depending on the exact inner diameter of the hoop. Its close enough that you would have to physically try the wheel on the car. Any 18" wheel will work with the Tru Turn.

Our only direct in-shop experience with fender clearance is with the Camaro..I don't know how much more or less fender clearance a Firebird fender has.
On a Camaro...if you use a 9.5" wheel with a 5.5 backspace and standard height subframe bushings there will be no fender mods neccessary. With a 10" whee; and a 5.75 backspace and 1/2" height subframe bushings [which will lower the ride height by about 1/2"] you'll need to clearance the outer/inner fender slightly for tire clearance. If clearanceing is unacceptable, use the 9.5" wheel with the 5.5 backspace.

[jlwdvm]

Would the V40"s be considered cast or Billet or somewhere in between?

[Tim john---]

I was wondering what your intent for the rear end that you will be removing for I may have interest. Is it a correct set up with the spring perches for the Firebird or something else. What was the doner vehicle for the rear end you plan on removing. I travel through your area a couple times each fall for hunting purposes, I was just by there last month (went fly fishing with friends in Wyoming). I love to hunt, fish & trap and travel often to do so. I will be heading right thru your neck of the woods around Halloween. Please let me know on the rear end when you get a free moment and how complete it is. I would sure love to stop by on my way through sometime and see your car and copare some notes. Take care.

Tim john---

[jlwdvm]

I'm not sure what the donor car was, but I can get you some numbers. It is still bolted to the car, but will be out soon so I can get the 4-link installed. It has new multileaf springs on it now and is in black paint with rebuilt drums on it. The fit and finish on it is great! The drive shaft fit well with the 455 and Muncie bolted in as well. I have a lot of parts to get rid of including complete restored front suspension with poly bushings,Brand new Pypes stainless 2.5" headers to behind rear tire with Race Pro mufflers (test fit and ready to bolt in), bolt-in frame connectors, new radiator, rear end , leaf springs, etc. I'll be chasing Iowa bucks from about Halloween through Thanksgiving. Let me know if you want to stop by.

[Tim john---]

The heck with the car stuff, it is hunting season ! Hunting, Fishing & Trapping are the air that I breathe and I truly enjoy the great outdoors. I shoot a traditional recurve bow with homemade arrows and have not missed an archery season since 1975. But in regards to the car stuff and seeing that I am only going slightly modified compared to you I am sure there are several items that will be of great help in my adventure putting this car back together. Please PM me your contact information and we can certainly stay in touch through out the fall. Stay safe out there in the big woods and do stay in touch. Thank You.

Tim john---

[Buryingthesun]

On the front:
If you are going to NOT use the Tru Turn system you will be limited to a 245mm tire on an 8" rim with a 4.75" backspace.

Im not running Tru Turn system and im running a 255mm on an 8.5" rim with 5" backspace on mt 67'

[rickpaw]

I an finishing up installing a Chris Alliston 6-point roll bar.

Do you happen to have pictures of the roll bar installations?

[bret]

Im not running Tru Turn system and im running a 255mm on an 8.5" rim with 5" backspace on mt 67'

And what modifications did you do to the oem Camaro steering arm to get clearance? Or are you using the Chevelle steering arm? The Chevelle steering arm will give you clearance but unless you modify the rest of teh steering linkage significantly the bumpsteer will be pretty bad.

The other way to get wheel/steering arm clearance with that combo would be to use the oem drum brake spindle with an aftermarket [or custom built] disc brake kit. That combination sits the wheel mount surface outboard by about 1". But that would seem to cause a lot if tire/fender interference unless the ride height is really high.

[jlwdvm]

Hope these come up:

[rickpaw]

Thanks for the pictures. Do they come pre notched? I will have to save up for the roll bar.

Back to original topic. Sorry for jacking the thread.

[Buryingthesun]

And what modifications did you do to the oem Camaro steering arm to get clearance? Or are you using the Chevelle steering arm? The Chevelle steering arm will give you clearance but unless you modify the rest of teh steering linkage significantly the bumpsteer will be pretty bad.

The other way to get wheel/steering arm clearance with that combo would be to use the oem drum brake spindle with an aftermarket [or custom built] disc brake kit. That combination sits the wheel mount surface outboard by about 1". But that would seem to cause a lot if tire/fender interference unless the ride height is really high.

Im have OEM Firebird steering arms.

Im glad you posted about the aftermarket brakes. I think I might have an issue once I swap over from my factory drums to the Wilwood's I just ordered