*IF* you go HEI off the 'Internet',
Then beware the distributor.
Wrong install heights, wrong distributor gears, 'China' components.
There is no 'Junk Yard' or off the shelf swap for a 'Correct' HEI since Jeep never used an HEI.
You are limited to the offerings from 'Internet' retailers that don't always get things 'Correct',
And they WILL damage your engine.
If you want an HEI, then go with the $300 version from DUI,
People report virtually NO failures with DUI over the 'E-bay' offerings.
If you aren't afraid of a little wiring, you can do a swap to the Jeep/Motorcraft distributor for about $60.
A Remanufactured distributor from the parts stores WILL NOT destroy your camshaft gear, have the correct install height so the gear rides in the correct position on the camshaft,
And it doesn't have the 'Spark Energy' control problems the HEI/clones do.
For a 304, that's a distributor from a '79 Jeep CJ with 304 engine, it will drop right in.
Then you do an upgraded cap, rotor, plug wires so you get the spark energy where it's supposed to be...
See signature line below for those details...
Then you use a GM HEI style module to drive your new ignition, which is pretty simple since you are coming over from a Prestolite system, the wiring is already in place...
Again, see Prestolite upgrade in my signature line...
THis thread http://www.jeepforum.com/forum/f8/ig...jeeps-1302352/
Scroll down to post #4 & #5 and see if this is something you can do...