Wheel and tire suggestions for my 76 Formula Firebird

[Formula400]

Hi all!

Wanting to replace my current 17" rims with some new 18" or even 19" rims.

Was thinking of getting myself a set of ccw rims http://www.ccwheel.com/files/wheelprofiles-display.php?id=SP20 but note sure what my wheel wells would take. (car not moded inside the wheel wells).

Seeing as the 19" rims cost the same as 18" rims I wouldn't mind going up a size but if I do that I won't come close to the original tire size of the car. (like 295/40/19 gives a 28.3" diameter while the original is at 27.4")

The closest would be 295/40/18 witch clocks in at 27.3".

But again not sure my car could take those sizes just goin by what some have suggested for 73 firebirds and 71ones not sure if there was a change on the 74s and onwards concerning wheel wells on the birds.

Up front would 275/40/19 work?

Is the backspacing 5.5" on the rear and 4.5" on the front the way to go with out having a car that wants to "wiggle" on the road? (some bad roads up here...)

Well any suggestions and input would be nice for this black 76 Firebird.

//Sven

[OLDFLM]

SWs red 73 TA had 255/40/18s up front and 295/35/18s out back as a baseline, without any mods or rubbing.
I think I'm gonna run a step bigger sidewall with 255/45/18s up front (some have already run this size up front without issues) and a 295/40/18 out back. Falken just released this size in their 615 series and I think they are the only ones... If you want to stagger them you could run a 255/40/18 up front and a 295/35/19 out back and have the same size sidewall front and rear but with staggered 18/19" rims... I've also seen some running the 28.3" 295/45/18 out back on second gens... hope this helps with your decision.
V/R,
Ty

[Formula400]

SWs red 73 TA had 255/40/18s up front and 295/35/18s out back as a baseline, without any mods or rubbing.
I think I'm gonna run a step bigger sidewall with 255/45/18s up front (some have already run this size up front without issues) and a 295/40/18 out back. Falken just released this size in their 615 series and I think they are the only ones... If you want to stagger them you could run a 255/40/18 up front and a 295/35/19 out back and have the same size sidewall front and rear but with staggered 18/19" rims... I've also seen some running the 28.3" 295/45/18 out back on second gens... hope this helps with your decision.
V/R,
Ty

Hi Ty!

Thanks for your input!

Do you know if there is any differences between a 73 and a 76 in regards of wheel wells? Just don't want to sit there with new rims that simply wont fit inside the wheel wells.

//Sven

[OLDFLM]

All 70-81s should be the same...

[Formula400]

All 70-81s should be the same...

Hi!

OK, then it's 255 up front and 295 at the rear.... Jesus that is a lot of rubber... :D :hail:

Thanks guys for the help.

//Sven

[adynes]

I thought the early birds didn't have the seatbelt hump. You might want to check a F-body specific forum.

[Formula400]

I thought the early birds didn't have the seatbelt hump. You might want to check a F-body specific forum.

Hi Adynes!

Thanks for your tip!

Checked yesterday and I got a hump in front of the rear wheel on the inner wheel well.

It felt like I couldn't go much wider than I already have. (it was abit more than an 1" between this hump and the wheel side and I'm borderlining on the outher wheel well as is with my 255/45/17 wheels at the moment.

For the owners of birds 73 and older could you please check if you have this hump on your car?

I'd appreciate the info.

Best regards
Sven