RickKlem

I Have a 1977 911 S, and I’m in the process of updating from a 2.7 to a 3.0 L and I have a few questions that I need answered.

First, Is the sending units used on the 2.7 the same as the 3.0 or do I need to change my gauges and if so which ones need to be changed? Also is it better to change the gauges or the sending units?

Does the same fuel pump, fuel accumulator, and fuel filter from the 2.7 work on the 3.0 L or will I need to change them?

I don’t have the motor yet so I don’t know if it has an O2 sensor on it. I ‘m adding a set of SSI heat exchangers and a 74 style muffler, the motor is a 1980 3.0L, the question is will this motor have a O2 sensor and if so should I order my heat exchangers with or without the hole for the O2 sensor. I have heard that the car will run bad if I do not plug in the O2 sensor, can some one tell me the correct answer.

Thanks for the help

Rick
1977 911 S

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john brasfield

I did my 76 with a Euro motor, had no o2 sensor, but I think you will kave to make accomoditations for it. The fuel pump is the same, I did have to move the accumulator a little as my hose was short, I think. Tou need the six pin CD box, and a thac from a SC. you will have to find the black/purple wire to the tach near the box and add it to the 14 pin connector. Overall, it was an easy swap, although it took me some time to get the tach working, but I did it. It is a good swap, make sure you have everything clean and done right so you don't have to pull the motor again. Get a new clutch, check the head studs and retorque, mine had two broken studs and we rebuilt the top end. I had the flywheel cleaned up and replaced the rear main seal.
Good luck,
john Brasfield