wheel/tire to wheelwell clearances, 64 chevelle

[64Chevelle]

Hi,

I'm trying to fit C5 corvette wheels on my 64 Chevelle. The front is working out ok with correct spacers but the rear seems a bit tight. The C5 rear is 275/40R18.

I have cut away the fender lip and lightly massaged the inner wheelwell with a hammer to bend it somewhat inboard.

What kind of clearances should I have at a minimum towards the inner frame/wheelwell side and the outer fender lip? It depends of course with how much suspension travel I've got with the drop springs (approx 150 lbs) in there now.

The problem areas seems to be the top of the wheel hitting the inner, upper wheelwell and at the passenger side the rear part of the wheel scrubs the fenderlip. I have measured and the axle is pretty much perfectly centered but I guess the body could be somewhat misaligned with the frame.

[PRRC]

1/2 inch clearance. is what we shoot for.

[64Chevelle]

Thanks, I'll aim for that as well, a little more if I can get it, but it's tight in there...

[PT Goat]

275 is going to be very tight in the rear of a '64/5. On an 8" wheel, you need 4.5-4.75" backspacing to get 1/2" clearance with a stock-width rear.

[DriverzInc]

When I measure a car in house for custom wheels, I shoot for .75" to the inner wheel tub, and .375" to the outer wheel lip.

The first place a tire will rub with body roll is at the inside top edge of the tire.

Good luck man, that is a wide tire for that car....

[gearheads78]

Measuring for wheels I mocked up without spings and shocks and tested about 8 different positions of suspension position and rotation. 1/4" is my inside and outside clearance at worst case suspension rotation. After about 500 real world miles I have no contact.

[LSXfan]

Thanks, I'll aim for that as well, a little more if I can get it, but it's tight in there...

ever get this worked out ?

[USAZR1]

My experience is that an 8" wheel on a 64-65 w/stock width rear requires a minimum of 4.75" of backspacing. Optimum is 5". A 17x9.5" wheel & 285/40/17 tire is the widest combo I've seen on the rear of a 64-65 and those wheels had 5.875" backspace. I don't think any metal trimming was necessary but it was a snug fit.

[LSXfan]

so a 17x9.5 with 5.75 BS and a 275/40/17 tire is doable ?



sorry for the hijack

[USAZR1]

so a 17x9.5 with 5.75 BS and a 275/40/17 tire is doable ?
sorry for the hijack

Not sure 5.75" is enough backspacing. Both the cars I know about had 5.875. One had 285/40/17's and the other had 275/35/18's. If I were going to give it a try,I would get the wheels with 6" backspace. That way,if 6" was just a tad too much,an 1/8" or 1/4" disc brake spacer could be used to optimize the backspacing.

[LSXfan]

cool, thanx for the info !

[USAZR1]

Not sure 5.75" is enough backspacing. Both the cars I know about had 5.875. One had 285/40/17's and the other had 275/35/18's. If I were going to give it a try,I would get the wheels with 6" backspace. That way,if 6" was just a tad too much,an 1/8" or 1/4" disc brake spacer could be used to optimize the backspacing.

I went back and did some more research on this and my numbers were off a little bit. My friend's 65 El Camino with 17x9.5 rear wheels and 285/40/17 tires was running 5.625' of backspacing on those wheels. The rear wheelwell lips were rolled slightly,too. With that fact,I'm thinking that a 5.75" backspace would be close to optimum on a 17 or 18x9.5 real wheel and I would stick with a 275 tire in either a 35 or 40 series aspect ratio.

[LSXfan]

thanx ,man ! I really appreciate the info..