Hello! I’m about to purchase a 1984 base model vette and I was wondering if it would fit the later year model c4s 17x8.5 rims or would I need an adapter?

 

The later (88-96) C4 17x8.5 wheels had 56mm offset, which is 24mm more than your 16x8,5s. They might fit without interfering because they're so skinny, but they will look odd. You'll want a 1" spacer or adapter.

 

would I be able to run after market rims on it at that same size if I use the adapter?

 

You can run any wheel up to 11" wide and 16-19" diameter* with the proper net offset and bolt pattern (5x20.65, not 5x120). "Net offset" means the wheel's offset minus any spacer thickness. You basically need an offset that keeps backspacing to 7.25" or less and doesn't cause the tires to poke outside the fenders. A net offset in the range of 32mm-38mm will work for you. If you go wider than 10" it starts to become fairly critical. The narrower the wheel/tire, the more room for "fudging" the offset you have.

*There are some 15s that fit, but I'm not sure about all the brake clearances so I'm leaving those out. I know some folks have used 20s, but they look goofy on a C4 and getting a short enough tire is a real problem.

 

oooh ok, sorry wheels are not my forte, I saw a Fitment that had a poke Fitment, about 1.5in spacers on it I think but it rubbed I want that fit me too but with out the rubbing and every forum either says you need an adapter for the larger rim sizes or that you can put them on. But I didn’t realize you could fit the 17x11’s on the 84

 

If the tires poke out past the fender edges, there's a good chance they'll rub on the fenders when the suspension compresses enough. A 315mm-width tire on an 11" wheel is about the max you can do without poking too much. But at that width, you have to really get the net offset correct. On a later C4 (88-96), I know for a fact that 50mm net offset is perfect. I don't know for sure about the earlier C4s because I don't have actual experience with one. However, 32-36 is the range to shoot for.

To give you a visual of what I'm talking about, here is my 96 with 315 tires on 11" wheels with 50mm offset:


If the tires stick out any more than that, you start to risk rubbing on the fender edges. For your early Vette, the only difference is that the hubs are about 3/4" inward from mine. So these same wheels and tires I used would sit inward about 3/4" further on your car, and they would rub/hit things on the inside. So to get this same placement on your car with the same wheels and tires, you'd need the 3/4 spacer. If you could find 11" wheels with an offset of 32-36mm, they would fit like this without using any spacers.

For the 8.5" wheels (with either 245mm or 255mm tires, I assume), you have a lot more "wiggle room". But to look proper, I'd still suggest shooting for the factory's 32mm net offset spec.