I have a 1998 3500 with a 24 valve and 5 speed that needs another engine. I would rather put a 12 valve in but realize I have to have a crank signal for the charging, tach, etc. to work. I have the option of a '98 12 valve engine that has the port for the sensor but don't know if the tone ring is on the crank. If it is not what is the possibility the '98 12 valve crank is machined to accept the tone ring from the 24 valve crank? If neither option will work, I can put the 24 valve crank in the 12 valve correct?

 

The tach and the alternator (and a/c I think) work off of the cam and crank sensor.

I am swapping a 12v in my 99, but I am using my block and crank from my 99. You will also need to get a cam sensor adapter for the 12v front case, which will replace the timing pin(or whatever it is called).

 

Correct me if I am wrong but I do not think I need to keep the cam sensor on a '98 only on a '01-'02. I think the a/c, charging, and tach operate off the crank sensor only. I am still curious about the tone ring though. Anybody had the oil pan off a '98 12 valve? May have to pull the sensor port cover on the 12v in my 2500 and hope I can see in there.

 

I would venture to guess that the crank in a 98 would be machined to accept the tone ring, but if not, toss the 24v crank in it.

Cam sensor isn't required for the 98-00 trucks, but it will cause a code. But you will have codes from no VP or APPS anyway.

 

Thanks, I think I'm going to give it a try.