i have a 82 firebird 305 that i swaped a newer pair of heads on (85 i think). so its new time to drive the motor but the ect sensor that came with the heads is completley broken. my old ect sensor (3/8 pipe fitting size i believe) is too small for the hole. i was told if the hole is bigger its the two wire ect sensor and my ect sensor is the one wire. and its kinda of a big deal cuz im not driving the freshly rebuilt engine without knowing how hot im running. what can i do? try and find a 3/8 to whatever pipe fitting and hope the sensor sticks into the head far enough to give me a proper reading? to convert to two wire? what kind of trouble am i looking at converting to two wire when it comes to my temperature gauge at the dash?

My 88 305 had a one wire sensor. It looks almost like a knock sensor with a weird wire connector. If I hadn't taken the wire off I never would have thought it would go on that sensor. Maybe try a 88 temp sensor?

You use exactly the same type sensor correct for you car
and a adapter bush to fit the sender up to the larger hole.
Will work fine

1/2" to 3/8" NPT reducer from any parts shop
see
http://www.summitracing.com/parts/FRA-491204/

your local hardware store will have this as well in the plumbing isle

Thanks guys, i have my old sensor so ill get a 3/8 to 1/2. that should do the trick. take care guys