New wheels & tires for a 68 300hp car

[David M.]

https://www.wheelvintiques.com/wheels/32-series-corvette-style-rallye-chrome.html

We want to "fill up" the wheel wells just a bit fatter than the stock appearance. We want to avoid any rub, turn radius interference or other fitment problems.

Would a larger offset achieve this somewhat fatter look we're after, say 4 or 4.5" on a 7" wide wheel?

Or should we go with 4" offset on an 8" wheel with a 215 or 225? The 8" wheel ranges from 4, 4.5 and 5" backspace. No 3.75"

Way too many choices. My head says 3.75" back space with P215/15" tires should be what were after?

Anyone have pics of this all chrome wheel on their car please attach them.

Questions, comments, advice welcome.

TX in advance!
Dave

[Paul D.]

Re: New wheels & tires for a 68 300hp car

I would suggest the tried and true 69-82 size wheel (15X8) and 225-70 15 tires . That should fill up the wheel wells properly without worry of interference. Chip.

[Duke W.]

Re: New wheels & tires for a 68 300hp car

The unique to'68 Corvette 7" Rallys have -0.28"' offset. There are also zero offset 7" Rallys that were installed on G-bodies, but they will result in insufficient rear spring clearance. That's why Corvette had the unique offset 7" Rallys in '68. The 8" Corvette Rallys have -0.50" offset. I would install those if you're not doing judging, and the tire sizes you should be looking at are 215/70R15 and 225/70R15. Unfortunately, most will be low speed rated without a nylon cap belt. The tire landscape is constantly changing, so do a Web search on those sizes and search the big online retailers. Also search this forum. George Jerome recently discussed installing a set of Vredestein tires that are specifically designed for vintage sports cars.

[Patrick B.]

[David M.]

Re: New wheels & tires for a 68 300hp car

No, no judging going on. Doesn't look like Vintiques offers -0.5" unless Im not looking at or understanding the size availability correctly? I know how to measure for offset.
I see 3 sizes offered in the 15 x 8" all chrome or argent silver wheel -4, -4.5, -5". Unless they dont know their decimal system? Ill call them. Thanks for the replays. Keep em comin...Time to go shopping.

[David M.]

Re: New wheels & tires for a 68 300hp car

Just got off the phone with Wheel Vintiques. They said their 15 x 8 with 5" backspacing is what we want. They didnt want to here negative this... that... or 0.28" or 0.50" I had to convert that to mm. So 127mm = ~5" offset(4.999...) or better described as back spacing. Sound right to you guys.

Second question is we are also looking a old school Cragar SS 5 spokes. Some come with concentric acorn lug nuts some come with the shank style. As an engineer I see benefits to both designs but Ill assume I want the OEM acorn concentric nuts for a better stronger clamping force???
I think the shank style maybe designed for the uni-lug wheels which we do not want but I do like the increased stud engagement. Or is this engineer over thinking it as we all so readily do...lol

[Duke W.]

Re: New wheels & tires for a 68 300hp car

Half inch negative offset on an 8" wheel would be something on the order of 3.5" backspacing. Those guys are morons. Find a vendor who knows what they're talking about.

[Patrick H.]

Re: New wheels & tires for a 68 300hp car

As has been already mentioned, I'd look for a nice set of original 8 inch rally wheels used on 69-82 Corvettes. They made millions of them, so it's not like they are uncommon, and they are usually quite inexpensive. Check Craigslist, eBay, Corvette Forum, etc for some for sale. I would not mess with Wheel Vintiques and whatever quality they do - or do not - incorporate into their wheels.

Patrick

[Richard G.]

Re: New wheels & tires for a 68 300hp car

If you can find wheels made by GM that you like the style of and they fit I would highly recommend them.
I have dealt with way too many issues from aftermarket vendors on stuff that didn't function or look right.

As an example I recently put new rockers on my 63. They were reproductions and installed fine and looked good in the shop.
I was happy till I got them outside. They looked bent. Turns out the painted black lines are so crooked they look wavy in the sun.
Another piece of junk. Will have to strip the black and repaint them for them to look right. Avoid the headaches if you can.

[David M.]

Re: New wheels & tires for a 68 300hp car

Argh...we purchased new Cragar SS old school five spokes and they do not fit. They interfere with the rear caliper, of course. Not sure on the fronts but it a moot point now. Not enough dish on the Cragars. We went with 8" rims and they are way to close to the E brake cable bracket as well. So 7" wheels will be purchased. But what off set? Summit and one other retailer recommended this exact wheel.

The OEM Rallyes have a what looks to be a 3.75" off set. The wheels on the car now have a 4" off set. So do the Cragars. The Cagars are missing the dish required to clear the outer face of the caliper. The Cragar mating face maintains parallelism all the way out to the hoop IE Flat from the center to the rim. Where as the OEMs and the current aftermarket wheels have that dish to clear the caliper face. In other words the OEM and current wheels have a "hat that stands the wheel off the rotor hat sufficiently(as GM intended). Currently there is a 1/2 inch spacer sandwiched between the rear wheels. I dont like that as it reduces the stud engagement. Im concerned with safety. Im trying to be talked into OEM Rallyes but we really like the Cragar SS look.

I believe Im measuring correctly. Im putting a parallel block on the rear face of the hub on the rim and measuring from that face to the outer edge of the rim.

Is there a specific caliper for 68s? We did the rear calipers a while back and they came from Ecklers or C.Central I forget which.

I know some of you have Cragars and they fit. What are we missing here? I should have taken pics for visuals but we were in a hurry today as we had a tire appointment set up for next week.

[Mike K.]

Re: New wheels & tires for a 68 300hp car

David,
If you do not want the tires to rub the inner wheel well, take Patrick Hulst's advice.
I had fatter tires on my 68 and big rub problems.

[Patrick H.]

Re: New wheels & tires for a 68 300hp car

You went from getting repro rally rims to getting Cragars?

The Cragar specs have been "off" for at least 20 years, probably longer. If you want to use those you need to find a vintage set with the correct backspacing.

If you want to use the ones you have, you need to either run spacers between the wheel and hub, or have the back of the wheel "fly cut" a bit so they clear the calipers. Neither is a great option.

[David M.]

Re: New wheels & tires for a 68 300hp car

Ya Im going with 7" rims of some nature as soon as I figure it out. Nothing fits quite like OEM! You'd think Cragar would have this figured out by now. There a bunch of us that would like to run these wheels. Enough so that youd think they would cater to it? (Id prefer new not old pitted crap).
Ill let you all know what we end up with.

[Patrick H.]

Re: New wheels & tires for a 68 300hp car

Ya Im going with 7" rims of some nature as soon as I figure it out. Nothing fits quite like OEM! You'd think Cragar would have this figured out by now. There a bunch of us that would like to run these wheels. Enough so that youd think they would cater to it? (Id prefer new not old pitted crap).
Ill let you all know what we end up with.

The current market for new Cragars that fit a 68-? Corvette is essentially zero. As such, they years ago limited the number of part numbers they carry and don't make the correct ones any more. So, while you feel that there are "a bunch of us that would like to run these wheels", Cragar apparently does not agree.

You might get them to agree to a one-time run, but you would likely have to do a group buy of X number of sets.

Also, its not rim width but backspacing AND curve of the spokes that is getting you. They make 7 inch ones that don't fit either.

As funny as it sounds, I think they make a 17 inch rim that fits fine.

[Gene M.]

Re: New wheels & tires for a 68 300hp car

The rear shock mount becomes the rear obstical. As in the front the turn lock to lock with the fender opening is the limit.