when looking at the engine block from the side does anybody know where the exhaust valve is located? 11 O-clock, 1 O-clock, etc?

 

Why do you want to know?

 

Good question Spike.

 

so I can index my new spark plugs when I put them in by pointing the ground electrode towards the exhaust valve

that is the only reason bosch +4 plugs help, it just happens to fire on the sweet spot electrode from time to time. I bought some iridiums and I want them to fire in the sweet spot every time.

 

Ok, but why?

 

a more complete burn which translates into increased horsepower and improved fuel economy..not much but every little bit helps

 

Fair enough.
Ii wont do you any good but if it makes you feel better then go for it.
I do not know the answer to your query, sorry.

 

indexing plugs has been proven to increase hp/fuel long ago..why do you think +4 plugs help sometimes?

 

I have never thought about it. As much as I live and breathe LR I have never thought about spark plug indexing or the +4 spark plug. I dont use the +4 plug...

 

I would want to be more interested in torquing the plugs to the proper specs.
This is a very out dated, 50 year old engine and it will take a lot more the indexing to help it.