The MGC with it's 6-cylinder engine used a bigger wheel than the MGB. The MGC tire of choice was a 165R15 classic tire. The tire we would recommend these days for an MGC would be Pirelli's 165HR15 PIRELLI CINTURATO ™ CA67. The looks and handling of this tire is perfectly suited to an MGC.
Original MGC Tires
Often with cars like an MGC people think a bigger tire will improve the car. If that had been the case MG would have fitted a bigger tire themselves. Low-profile tires came out in 1968 long before the MGC ceased production, and they could have used a 185/70R15 tire, but they didn't. However, if you do want a bigger MGC tire then fitting a period correct tire with a carcass that is designed for such a job will diminish the handling deficiencies that oversized tires bring. 185/70VR15 PIRELLI CINTURATO ™ CN36 is the perfect tire for the job. It's rounded shoulders will maintain progressive handling while at the same time providing a wider footprint that some people want.