'86 944T wheel size

Vehicle Information: Model(924/944): 944 Turbo; Year: 1986; Engine (type, size, modifications): MAF, wastegate, boost controller; Total Mileage: 100,000;

Would you know what is the biggest size wheel that would fit, with spacers if needed, on the rears. I recently purchased a set of hollow spoke 8"s & 11"s turbo twists, which I'd like to use on my Boxster S and my 951 to bolt on for racing events. I don't have tires on the 11"s yet so I can't test them out. Pondering whether to keep them or sell them. I'll base my decision on fitting. Right now I have 10"s in the rear of the 951 and fit just fine.