I've been able to find center pieces but the wheel is what I'm having trouble finding. Would the center pieces all be 5 on 5?

http://images39.fotki.com/v1228/photos/2/213641/6400484/106-vi.jpg

The closest thing I could find but not sure if it would work with the centerpieces at summitracing.com:

http://static.summitracing.com/global/images/prod/large/usw-94-5812.jpg

The wheel you have there is nothing like the 9C1 wheel above. The 9C1 wheel, in and of itself, is an updated take on the old Truck Rally wheel, with larger vents (holes instead of slots). The wheels are 5 on 5 (or 5 on 127mm). The center caps you have will not work on your car unless you convert it to 5 on 5. Niether will the 9C1 wheels (as you have the 5 on 120.5mm or 5 on 4.75"). However, you can get a set of Cragar 342 NASCAR style wheels (or Unique 42 series, Unique Wheel makes the Cragar powder coat steel wheels, so it's identical in every aspect to the 342), or American Racing AR-767 as these all look the same and are availabe in your bolt pattern.

or you could always check out a set of these

60s rallys
http://rockcrawler-mrt.com/baseimages/RALLY%20WHEEL.jpg

i have seen many 80s caprices and 80s malibu with these wheels. they are real easy to find in the after-market and if you look you will even find them in black. they (depending on what car and year) come in an 8 inch variation. my buddy ran 15X8s in the rear and 15X7s in the front on his 81 malibu.

black with trim rings
http://memimage.cardomain.com/member_images/2/web/746000-746999/746398_80.jpg

The center caps you have will not work on your car unless you convert it to 5 on 5. Niether will the 9C1 wheels (as you have the 5 on 120.5mm or 5 on 4.75").

So Silcon do they make the chrome center pieces with the Chevy logo in the 5 on 4.75 pattern or is the only way to get that 9C1 wheel look is to do the 5 on 5 swap over?

On the center caps - you might be able to find something on an older S10 truck, but it's not going to be exact.

Those center caps actually bolt onto the rim with 3 bolts. The bolts are located between the lug nuts (with no bolts between 2 sets of lug nuts).

The 60's Chev rally's shown in one of the pictures were used from ~1967 to 1981. They came as 15x6, 15x7, & 15x8, as well as 14" versions. The 15x7 and 15x8 are by far the most common. The 15x6 is uncommon to find, and was use on 1967 and possibly 1968 vette's, and 1967 to 1970 Impala and Parisienne with the front disc brake option. On the Impala's and Parisienne's you could get them in two flavours, grey with trim rings and either flat cap (1967 on Impala's and 1967-70 on Parisienne's) or the more common tall caps (1968 to 1970 on Impala's, and 1968 + on Camaro's, Chevelle's, Vette's, El Camino's, and Monte Carlo's), or if you wanted wheel discs with your disc brakes you would still get the rally rim but it would be black in lieu of grey.

If you want to convert to 5x5 bolt pattern find a 1991-96 cruiser or cab at the wreckers and take the front steering knuckle c/with everything and the disc brake rear diff and install them into your car. I'm sure you can find info on-line to convert to rear discs. Or the other option if you don't want to change diffs is to pull the axles on your diff, have new splines broached in them for the bigger pattern 5x5 stud, and drill larger pattern holes in the drum at the same machine shop. Or if you like wagons they were all 5x5 from 1977 up.

There was also an optional 15x8 steel wheel on the 1991-96 cruisers. This was the optional 15x8 truck rally wheel with the aforementioned slots. I've seen a Caprice SS interceptor car with this option.

All of the centres used on 1991-96 cabs and cruiser were the same centers used on 5 bolts pick-ups and vans from the late 70's until I believe the early 90's, so there are millions of them out there. They're even the same GM part number. The only difference between the car and truck versions is the screw used to attach the cap to the rim; the cars use a screw with machined metric threads and the trucks use what looks like a wood or sheet metal screw. If you have a Buick Roadmonster you can remove the Chev or GMC emblem and install a Buick trishield from the wire wheel centres, that way you won't feel left out of all this Chevy fun.