brick1234

it really comes down to how much you want to spend and how you want it to look everyones taste is different imo.
if memory serves correct stock aluminum 20lbs and stock 8 inch rallys about 28lbs. a cheap 15in aftermarket rim like the eagle alloy 101 are 14lb or 15lb when i weighted them, now some of the higher end forged/billet 15 inch rims weigh in at only 10lbs to 13lbs that are on my car now(7 in front and 8 inch back).

IronMaidens2.0

Ok so I am looking at 17x8 (F) and 17x 9.5(R)


What tire choices do I have to stay in the 27dia range .


thinking about 255(F) and 275(R) .

lionelhutz

Try this site. Pick the rim size and then you get a listing of the tire sizes by their diameters. Pick a size and you get some tires listed or use the size to search other sites to see what is available. It makes it easier to go through the possible combinations like available 17" vs 18" vs 20".

https://tiresize.com/chart/

Krystal

It probably boils down to what you're going for.

If you want a better handling C3 ........ there is no arguing the improvement available in a 17" wheel and the vastly larger selection of quality rubber available to you today.

To really get the benefit though..... suspension changes are required too though.

I suppose you have to ask yourself....... "how far from "stock" do I really want to go?"

For me?

The answer was, "I want what I"m not supposed to be able to get. I want the smoother more compliant ride and I want handling that wasn't possible in years past when my car was newer"

Getting there happened through the use of a Fiberglass transverse spring in both the back of the car and the front of the car. No more coils in front and no more big *** leaf in the back gave me the smoother ride I wanted and a faster spring reaction.......way better shocks required to keep up were also part of the puzzle and then the much larger sway bars to keep everything flat in hard cornering.

After doing all this......finding the limits of a 255/60/15 BFG happens with little effort required. This is a tire designed for a period of time BEFORE cars could even approach anything considered "run of the mill" cornering potential today.

17" wheels are just about a no-brainer these days.

You almost have to go this route if your goal is far better handling C3.....not because a 15 inch tire can't be good.......but rather because the size has been all but abandoned by the industry.

Is a C3 worth the effort?

I think so. The 4 wheel discs are still pretty impressive all these years later, even in stock form........and your car, assuming it's a small block car, still has that near perfect weight balance between the front and back wheels.

Your car may not meet up with the newest Corvettes with super expensive rubber, latest suspension parts and all the "nannies" on board to help average drivers look better.........but if you have any skill of your own behind the wheel......your car can be turned into something pretty impressive..... you just have to decide if that is what you want or if the old school limitations are a big part of the nostalgia for you and your older Corvette. I wouldn't quibble with the thinking that says, "I bought an old Corvette because I wanted a true "throw back" to another era of automobiles. 15" rubber and a harsh ride are part of that."

69427

It's your car, and your money, and definitely your choice of what you put on your car.

I keep the 15" wheels and tires on my '69 (for street use) because I hate the looks of 17 or 18 inch wheels on our antiques.

I run various size wheels on the car for track days, as I'm willing to overlook the wheel aesthetics on those occasions.

I don't street race, so I don't need high dollar tires to get my car from one place to another. The 15" tires obviously don't have the grip of some of the 17 or 18 inch tires, but my car weighs about 400-500 pounds less than the average C3, and my lightweight rotors, calipers, and suspension components gets my unsprung weight down with the best of them.

It all just depends on what you want your car to do, and if you need extra expense tires to compensate for deficiencies in the suspension capability or the extra mass they have to stop.

Just one man's opinion.

Alwyn678

Impressive answer

Krystal

Thanks..... speculating about the differences is always difficult.......it get's far easier to make the comparisons when you've actually done it.

It wasn't especially "cheap" to do......but in hind-sight it was pretty easy.

In my case it's a Vette Brake suspension solution and 17" American Racing wheels......but I didn't do it all at once. I drove the car for a few years on the original 15" aluminum wheels and the all to common BFG 255/60/15....... same as many others who have chimed in already the thought of a 17" wheel doesn't look "right" would have found me in agreement.......but I've gotten used to the look and when I consider the MASSIVE improvement in handling from a better contact with the road.......there is no going back for me.

Night vs day improvement in handling capability is NOT an over statement for the 17" Goodyear tire replacement vs the old 15 inch BFG.

This car didn't need 17s to turn flat and ride better........but after the 17" conversion it now sticks the corners like eggs in a cheap skillet.

jb78L-82

Well said!

I continuously made improvements to the stock suspension one part at a time over 30 years so that I could gauge the improvements. After the poly upper and lower control arm replacement in 2006/7 and the custom blueprinted/rebuilt OEM steering box by GTR1999, I finally decided to let the OEM aluminum 15 inch rims go along with the awful 255/60/15 BFG Radial TA's for the 17 ultra performance summer only tires on SLP rims. I will never go back unless someone ever offers a copy of the OEM aluminum rims in a 17/18 rim. Not only is the handling and steering superb but the ride is fantastic! Drives like a modern sportscar!

zrc3john

Post some photos if you can....Down the line may be interested in changing up the old school look..

jb78L-82

Post #19 on this thread and elsewhere as well on this thread.

Also post #66...the red C3 with chromed SLP's

Capt. Shark

Indeed. Krystal is a financial guru and a car nut, too.

Krystal

I know weren't directing the question at me......but......here's my car on 17" American Racing's "nod" to the Cragar SS from the past.

The sidewall size is noticeably smaller than a 15" wheel tire.......but doesn't look as out of place today as it did when I first did it......I think I've gotten used to it through time and the fact that so very many sports cars and pony cars now wear a 19 or 20" wheel with much shorter still sidewalls today.





......and this is a shot of the front suspension....the adjust-ability of ride height and stiffness in the front done as easily as in the back with the Vette Brake fiber glass.... the better ride and grip......go without saying vs pound your kidneys to MUSH Coil Springs it replaces.

cv67

knows her way around a gym, too
17s are a good compromise there are more choices & getting more affordable. Perhaps one day just dont trust wheel spacers at all

Krystal

Wheel Spacers are only required if you just HAVE to have late model Corvette wheels.......if not......you can find plenty of choices that have the correct back spacing. I'm not running a "spacer" and I wouldn't want to either. I've seen some that look safe enough in the idea that they bolt to your existing lugs and then the wheel bolts to the spacer. Gone are the days of worrying that a spacer could allow the lug nuts to loosen unexpectedly......but I'd still worry about what this does to the way your bearings in both the front and back carry the weight and cornering forces of the car.

OldCarBum

"but I'd still worry about what this does to the way your bearings in both the front and back carry the weight and cornering forces of the car".

I talked with several suspension and wheel manufactures who stressed this point and strongly recommended not using wheel spacers and to keep the backspacing of a wheel as close to center line as possible.

ignatz

The important point here is, spacers or not, to get the wheel centered over the bearings.

mrvette

A 'spacer' is some cast aluminum POS that scared HELL out of me decades ago in a gas/svc. station I was helping a buddy out.....NFW them wheels went back on that car....

sometime back in '95 I got VBP to make ADAPTERS for my '72 to put '92/later updated to '89 Vette wheels on it.....'89 is better style, so I upgraded a couple years later.....I kept the same wheel centerline, so to make suspension loading the same....

the handling was THE single most improvement to the car....after that....rack steering hydroboost brakes VBP plastic 360 rear spring, Billy Stein shocks....

lionelhutz

If the final end result of the combination of wheel and spacer/adapter is the same offset as the previous wheels then the wheel bearing load doesn't change.

mrvette

I got a 'thing' over that term 'spacer'.....when that shituation opened my eyes long ago, and I wanted to put the C4 wheels on my C3....

I got in touch with VBP and we discussed measurements as to what was needed in MY case..... so 275/50/17 rear 255/50/17 front....

Krystal

VBP sells an offset trailing arm too that will allow for the use of a much wider rear wheel if that's how anyone wants to go...... might not be worth it though unless you need the rear arms rebuilt .......it's a pricey way to go if you'll be ditching perfectly good arms to get them.

I did my rear arms just about 10 years ago and the limited milage my car sees means I likely won't be doing that again anytime soon. A new engine in Sept really NEEDS more tire out back......nothing short of slicks will contain it's low end power.......I now regret having passed on the idea of the offset arms.

I tell anyone to just do them at rebuild time.....even if you don't need them for the wheels your running now.....they'll add very little cost to the job and they give you more room to grow if you need to in the future.