255 Tires on a 69

[DKz Garage]

Hey Guys,

Anyone have any luck with a 255's on the front of a 69? Specifically, I have a set of 255 35r18 Sport Pilots that I'm looking to put on the front of my 69 Camaro, stock sub-frame with Speedtech Control Arms/coil overs. I am "re-hooping" my Forgelines to a 8.5" width..... as the consensus is that a 255 needs a minimum of 8.5" rim. I'm currently running a 245 45R17 on an 8" wide rim with no issues. Any experience with this set up????

[c4racer2]

I had 255's on a 8" rim, but 8.5" is more ideal width. They should fit no issue with the right bs. 245 vs. 255 is only about 1/3" maybe 1/2" at the most wider.

[68Formula]

For what it's worth, on my '68, I did a test fit with a borrowed setup using 255s that were 25" tall and they seemed to fit with an 8" rim and 4.75" backspacing (only mocked it up and rotated the steering at ride height, no actual driving) and it seemed to fit (barely). Mine is a stock sub, Baer disc brakes, DSE UCAs, -1/2 degree static camber, and about +4 degrees caster. Decided I didn't like how the small diameter tires looked in the wheel arches... maybe not as big an issue on '69s. Going up to a 26" tall 255 would've contacted the rear fender during a turn even if I removed the fender bolt completely.

The total width difference accounting for the tire and rim differences should make the 255 setup about 0.4" wider total (so figure .2" less room per side). Most recommend about 6mm-8mm offset, so with an 8.5" rim that would be 5"-5.125" backspace (myself, I'd go towards the deeper side to be sure... giving up a couple degrees of turn radius is better than tearing up a tire. Or you could throw a thin spacer on). Recommend you replace your fender bolts with button heads to give a little more room than the hex heads provide, and smoother surface if contact does occur.

[Z06vet]

I'm running 275s on 9.5" rim w/ridetech suspension on stock subframe 69. 255 on 8.5" rim w correct backspace should fit easily. I have run that on a 67 a couple times before.

[68Formula]

I'm running 275s on 9.5" rim w/ridetech suspension on stock subframe 69. 255 on 8.5" rim w correct backspace should fit easily. I have run that on a 67 a couple times before.

What diameter was that on the '67? I wanted to try 255/40R18s but they would've hit the rear fender in a turn due to the diameter. Was that with the factory subframe? Also, do you recall your backspacing?

[DKz Garage]

For what it's worth, on my '68, I did a test fit with a borrowed setup using 255s that were 25" tall and they seemed to fit with an 8" rim and 4.75" backspacing (only mocked it up and rotated the steering at ride height, no actual driving) and it seemed to fit (barely). Mine is a stock sub, Baer disc brakes, DSE UCAs, -1/2 degree static camber, and about +4 degrees caster. Decided I didn't like how the small diameter tires looked in the wheel arches... maybe not as big an issue on '69s. Going up to a 26" tall 255 would've contacted the rear fender during a turn even if I removed the fender bolt completely.

The total width difference accounting for the tire and rim differences should make the 255 setup about 0.4" wider total (so figure .2" less room per side). Most recommend about 6mm-8mm offset, so with an 8.5" rim that would be 5"-5.125" backspace (myself, I'd go towards the deeper side to be sure... giving up a couple degrees of turn radius is better than tearing up a tire. Or you could throw a thin spacer on). Recommend you replace your fender bolts with button heads to give a little more room than the hex heads provide, and smoother surface if contact does occur.

Thank you all for the input! As noted in the response(s) I've gotten, the 255 35R18 is a bit shorter than the 245 45R17, and it's not a whole lot wider (about 5/8 - 3/4"?). I'm going at this very carefully, as the inner Forgeline hoops are not cheap and I want to get it right the first time.

[68Formula]

Thank you all for the input! As noted in the response(s) I've gotten, the 255 35R18 is a bit shorter than the 245 45R17, and it's not a whole lot wider (about 5/8 - 3/4"?). I'm going at this very carefully, as the inner Forgeline hoops are not cheap and I want to get it right the first time.

Could always re-hoop the Forgelines to 8.5" and then do a test fit with the just the rims and go with 245 if you're not sure it'll clear. Check your tie-rod clearance if going to the wider rim. Should be ok as long as your not using dropped spindles, tall spindles or taller balljoints.

[DKz Garage]

I'm running 275s on 9.5" rim w/ridetech suspension on stock subframe 69. 255 on 8.5" rim w correct backspace should fit easily. I have run that on a 67 a couple times before.

WOW! That is awesome...did you have to notch frame or wheel houses??