2nd Gen F-body (1979 Pontiac Firebird) - wheels & tires for Stock class

[Robert Swartz]

I searched through all the old tech stuff before I posted this. If it was in there, I didn't successfully locate it. Almost wish I were building a 3rd gen car (incidently, I do have one of those bodies in the driveway), plenty of info regarding those cars.

Since there are a few of these cars out there. Thought I'd ask to avoid the pitfalls.

First off, on the front of these cars, any special problems to look for as far as tire fit?

How tall a front tire can you run?

Can you use off the shelf wheels?

Or are there any backspace problems I need to be aware of?

The car has factory disc brakes on the front, now. Initially, I'm just going to rebuild the stock brakes (both front and rear) and use them. Down the road, I'll convert it over to something more liteweight. This will be one of those areas that can stand improvement, in both weight savings and performance.

Next, rear wheels. Being an IHRA car, I know I can legally run 10.5 rear tires. I'm just going to go with 9 x 30's. I've not jacked it up to look but I've read that it's a pain to put 10" tires under these bodies. At some point, I may want to convert this car over to run NHRA legal stock.

For 9" tires, use 15 x 8 wheels?

What backspace does anyone recommend?

The car has drum brakes on the rear. I am going to use the factory 10 bolt under the car. It's going to take a trip to Moser for axles, spool and a changeover to housing ends that do away with the c-clips. I've already spoken with them on this and have been informed as to what I need to do.

While I'm asking, what about tire recommendations? Both front runners and slicks. I have been told by another racer that radials are the way to go with an F-body? That's why I ask, I'm here to listen and hopefully learn.

[Greg Hill]

Robert I race a 71 Camaro in stock and run a 9X30 Hoosier Radial with 15 x 9 wheels with 5' backspace. Up front are 15x 3.5 with 26' Hoosiers and my son's car has 28' on the front.

[Dave Ribeiro]

Robert,

Greg, is dead on .... I run a 77-78 bird with 15x8 rears and 15x3.5 (28") front.
I have seen people run 10" rims on rear with a little work( 5" back space).. Yes, Hoosier Radials are the way to go ... Good Luck with your project ..

[Robert Swartz]

Greg & Dave,

Thank you for the response. That gets me in the ballpark. I can start fishing around at the swapmeets and whatnot. Go armed with a tape measure and see if I can stumble across a set of usable wheels, down the road. For the front, I'll probably spring for the lightest wheels I can find. The nose on this "Bird" is front heavy. I want to reduce some of the "rolling weight" for lack of a better term. Another reason to convert to a good lightweigth aftermarket brake in the future.

This begs another question. What about front springs? I was planning to "just use" the lightest Moroso front springs I could get. I already have a set of Competition Eng front shocks I'm going to try. If there's a better idea out there, I'd like to hear about it?

Originally, I was going to rebuild the front end. At present, it's in good shape, nothing excessively worn or bad. I'm going to forgo this for the present. Prior to installing my subframe connectors. I am going to change out the body bushings, I know those have seen better days! A good front end rebuild is something I can do at a later date.

For the rear, I'm going to get the Rancho shocks from Calvert. That will make the rear a complete Calvert setup with the Cal-tracs and monoleaf springs.