10 people
Depends on the size and enthusiasm of the clowns involved.
None will fit.
You can fit quite a few. Here's the web address for one: http://www.partsgeek.com/catalog/1973/volkswagen/beetle/carburetion/carburetor.html
When I was in high school, on Volkswagon Bug night at the Drive-in, we fit 17 high school kids in one.
The 1975 regular Beetle windshield will fit the 1971 Super Beetle.
You could probably fit about 10 people, but it would be about as comfortable as 10 people in a Volkswagen. My source? I've been up there. Had to book tickets 4 months in advance
People have done it but it's very hard. What WILL fit on your Beetle are the disc brakes from a 1969-on Karmann Ghia.
maybe 3 or 4
No.
a 912 Porsche engine will fit in a beetle
Porsche and Volkswagen have always been similar in design. Porsche engines will not fit into a beetle very easily. Just four bolts, three wires, one fuel line and one cable (only old Porsche 356 motor) .