Crank Shaft Pulley Timing Mark

I've got a 1958 CJ5 and as near as I can tell, it has a 1971 F134. It has a double crank pulley on it however it has a couple of "ticks" on it [not a large "V" cut as I have seen in some manuals] for timing purposes which are about an inch and a half apart from each other.

The engine is not currently running so I cannot just start it up to see which tick is the right one for timing. When I roll it over using the crank nut, the marks are so close, I can't get good indication which is correct. Valve cover is off, and in either position the intake valve is closed with clearence at the valve stem and difficult to see piston position through spark plug hole.

One tick, I notice, lines up with a hole on the back side of the rear pully. Am I going to have to get the engine running to determine which "tick" is right? Or does the hole on the rear pulley have anything to do with determining the correct timing mark?

 

Stock 1958 Cj5 had single pulley. M38A1 had double pulley, and the M38A1 pulley does often have a small hole on the rear that corresponded to the timing mark.
Not sure about 1971.

Possibly, one tick is TDC and the other tick is an advanced (BTDC) mark someone added for timing light use?

Pull spark plugs, rotate engine by hand. Perhaps you can find approximate TDC on #1 piston using a light, watching for when it reaches the top of the cylinder. Or carefully use a thin feeler of some kind. But it won't be exact. See if one of the pulleys mark coincides.

Go from there, get it running, then time it precisely to 5º BTDC or a tad more.

(Intake valve is supposed to start opening at about 9º BTDC of the intake stroke, if that helps.)

 

Thanks PeteL. As sometimes is usual for a Jeep this vintage, it is a "mish-mosh" of parts from one vehicle or another. I suspect it may have a military engine or, at minimum, parts from one as the fuel pump was the military variety, the fan blade is OD green as was the crank pully until I bead blasted it for some metal work and painting.

This is the engine number from the boss above the water pump: 1T58692. Does that offer any clues?

Good tips and I appreciate the info. Thanks

 

Engine numbers are not my specialty, but other members here may be able to help.

OD color crank pulley would seem to confirm you can use the hole as your timing reference.

 

Perfect...thanks!