brybrew

I know this has been discussed a lot and I think I've read just about every post in regards to this subject but not being a wheel/tire expert and there are a lot of conflicting information based on each others experiences and it can vary widely based on wheels and manufacture. I have a 69 Convertible, VBP fiberglass spring in the Rear with Longer bolts and a QA1 coilover setup in the front (Stock Upper/Lower A-Arms). I was looking at a set of the Rocket Attack wheels and wanted to see if anyone run these? (I've not seen them in the wheel/tire posts for C3's) With the Stock BS at 4" the one I'm looking at are 18x8 with 4.5" and 18x10" with 6" BS. Correct me if I'm wrong, but with this setup, would the front have more of a lip than the rear? (I am thinking the offset is the same for the 10" wide vs Stock but the 4.5" would bring the wheel .5" inward) I asked the manufacture and they did say they have a customer with a 73 convertible with these same wheels/sizes but could not say for sure. I assume a e-brake relocation but would I have the clearance the frame as well on the BS?

Wheel sizes:
http://www.rocketracingwheels.com/ro...yper-shot/p679

My next question is in regards to the Tires, to get at Least the same OD at the original 15" wheels, What series tires would be best for a 8"F and 10"R wheel? as they get wider I know the tire sizes adjust (So a 235/40/18 and a 285/40/18 are not the same height.)

Appreciate any and all help!
Thanks,
Bryan

terrys6t8roadster

Nice wheel choice. For my 69 coupe I went with 18x9 up front with 4.5 back spacing. Front suspension is all stock. The rear has a shorter glass spring from Van steel along with offset trailing arms.. The rear wheels are 18x10/5.0 b/s. The wheels are flush with the top of the wheel arches. Even with the offset T/As 6"s of b/s would never fit. T

Kacyc3

6 in bs without a space will hit the trailing arm even after the parking brake bracket has been relocated, chances are your longer bolt will also hit the wheel. I know my 10" bolts hit the zo6 knockoffs I had on my car and I didnt have to move the pb bracket for those wheels with the spacers I had.

cagotzmann

If going to 4.5" BS I would use 18x9 wheels , but it may be possible to go with 4.75" BS All round with 18x9.5 wheels.

I have the VB&P Street & slalom kit on my 78 with 4.75" BS & 18 x 9.5 all around, running 275R40 x 18 wheels. No mods to the factory suspension.

I did a 3d cad drawing based on my 78 suspension to determine the max offset that would work without modes. And that calculated to 4.75 BS and to get the best alignment
to the wheel arc a 9.5" wheel width worked best. As for Tire Dia 275 40R is about 26.65 vs 27 of the factory 25560R 15 tire which is very close. But looking at the wheels installed you will never see the difference.

brybrew

That is one beautiful 78 and the mini lites look awesome on it. I appreciate the reply’s! And the CAD drawing is defiently helpful! I’m sure the C3 with the rockets must be using spacers for the 10” on the rear wich I would want to avoid. Eventually one day, I hope to do the coilover conversion in the rear (van steel or ride tech setup) but that will be always down the road. To get the right backspacing, it’s sounding like I’ll have to go back to the wheel search. I love the forgeline GA3’s but not being a track car, I’d rather spend the money instead on other parts of the car. Spending 4K on wheels would not exactly be budget friendly but they are a beautiful wheel.

Thanks!
Bryan

gkull

You really don't want skinny tires on the front. stay with 255. I use a 9 inch F wheel with 4 bs. on the rear you could use a 6 inch bs wheel and 1.5 inch wheel adapters. I have 6.5 inch BS rears with 2 inch wheel adapters

mvette76

255/4518 on 18x8 with a 4.5” backspace on front 285/40/18 on 18x9.5 with 5.0” on the rear