"I've heard that D type requires a relay and J type doesn't"...wrong...both need power, and the way you wish to activate your switch and then supply it to the solenoid determines if you need a relay (bistable latching or regular) or not.

...it's amazing what "information" is out there...

OK Ron, instead of your 'judgment' why don't you answer the question, based on the information I supplied. We're not all as electrically proficient as you are.

I'm using the pull stalk; I'm using a stock OD indicator light; I'm using the required 4th gear lockout switch, and the solenoid (J type). That's the way I wish to activate the OD. Is a relay required? If not, then what would the circuit look like? If it is required, you don't need to say any more - I've done it that way before.

I'm just trying to learn something and help someone else out as well.