Trying to figure out what size wheels and the offset that will fit on my car. Its a 75 with the 911 lug conversion. Right now it has the gt flares, but I'm going to be installing the sheridan standard body kit. The front wheels will be 8" and the rears will be 10". So I need to know what offset I would get for the fronts and rears. Not sure if you need more information from me to get the answer if so let me know. Also whats the largest diameter rim you can put on. Most of the rims I've found are 17",18" and 19". I'm looking for some 16" but not alot are around.

Many of the 911/930 guys are starting to realize the tire selection for 16" wheels is limited. In fact the 17" tire selection is not once what it is today and many are now moving quickly to 18" wheels. Three piece wheels lets you build to fit your car. Fuchs can be made into 3 piece wheels, Fuchs can be welded into a 17" barrel and make a 17" fuchs that way, or you can just have a set of 18" wheels built to fit your car. For a time period correct look you could look for BBS centers and make a set for your car. I build 18" 3 piece wheels for 930, 911 widebody and 964 Turbo, 993 and 993, 996 TT cars. Just depends exactly what you want. I routinely make 9 & 11 x 18 and have made some 10 & 12 for a GT2 widebody 993 TT. Jim jdorociak@gmail.com
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Will a 18" even fit in a 914

I have 8.5 x 18 and 10 x 18's under a standard Sheridan body. My fronts were rubbing a little but I was running a 245/40/18 front and 275/40/18 rear Continentals and they were too tall for the car. If you run 18's, use a 30 series tire and they shouldn't rub. They are late a offset rim but I am using 3" rear and 2.5" front spacers which I wouldn't recomend using. Too much unsprung weight. I'm looking for some 18" deep offset wheels myself to do away with the spacers.

914junkie can you put up a pic of your car with the 18" rims.

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Crappy pics but it gives you the idea. Also, I don't know what you are running for power but if it's a stock 4, those big wheels are gonna slow ya down. I'm running a V8 with 250HP/300ft lbs of tq and even with that I couldn't believe how much quicker the car was when I put on 16" wheels with a tire diameter of 24" compared to 26". It was like regearing the car. Something to take into consideration when wheel/tire sizing.

What you are describing is the same thing that happens with the 18" wheels on the 911 and 930's the offset is really low ET 11 up to 25 vs the late model cars where it is 52 up to 65. That is why many have to use 2 & 3" spacers to make the late model wheels fit the early cars. Build to fit means instead of an 8" inner barrel I use a 6.25" on the rears instead of a 1.75" I use a 3.75 up to a 4.75" . I have attached additional pictures. this set is 8.5 front and 11.5" and fit a standard 911 with flares added. Jim

I dont want 18" rims, I would much preffer 16" with some meat on the tires. The problem is there are getting hard to come by that look halfway decent. I really like you rims but they don't make them in a 16".

17"s give the best opportunity for us right now.. 255x40x17 still available.. 17x9 still look ok and will fit on the back.. Rota is making a fuch knock offs with an SC backspacing..

225's are the biggest tire both in 15 and 16's in street tires on general availability..

Lindsey Racing, and Truwheel design widen Porsche Fuchs wheels. They can make you a special sized set to fit your car. 16 x 8 are available but expect to pay $500 each and the 16 x 9 also available, but I expect them to be $650 and up each. They weld two wheels together and can make wider wheels, with the offset you are looking for. 16 x7 fuchs are pretty cheap, so possibly you could run those up front and then have a pair made into 10's for the rears. Or -- BBS wheel centers 20 bolts these were available in 16 and 17" sizes, I know a post on pelicanparts.com where there were (4) centers for $1200, but then you have to go buy all the inner and outer rims. Have fun -- good luck. Jim