1980 911SC performance upgrades - supercharging or high-compression pistons

I brought this Porsche a few years back. The first and second gear synchos were short after a while. One day I dropped the engin, took apart the transmission and rebuild the tranny myself. That was two years ago, the engin is still on my garage floor.

I started to clean the engin itself by taking took off everything, including the exhaust and the intake, CIS. Now I have a motor with nothing on it. I am looking at engin upgrades now. I think the SC is a fund car to play with since it only weights 2700 lbs.

I live in California, so I wish to keep the catalytic converter. I know that it is illegal to change anything else, but I alway wanted to add a supercharger to that car if it can be changed back quickly. There are 50-states legal supercharger kits for corvette and mustangs, but I never saw one for 911SC!. Does anyone know of any besides the one in Knotsville which is not california legal.

If I do not supercharge, then my other option is high compression ratio piston and cylinder sets. With the 3.0 SC I can go to 3.3 litre with some machining to the case or to 3.2 litre without any machining. Has anyone out there done the 3.3 litre conversion? What is the maximum compression ratio for pump gas. I am thinking of crank firing instead of the crude mechanical timing advance in the distributor. Someone also recommanded changing to a cam with more overlap.

CIS can supply a lot of gas. I think it can easily supply a 400HP engin. I do wish to keep the car street legal for a while before I turn it into a race only car.

I have an 83 SC coupe with a 3L motor. I am interested with what info you have found & will share what I have.