Can anyone please tell me which is the correct dipstick for a 0-320-b2b  when used in a tail dragger (ie RV6) The parts catalog lists 2 models LW-14759 and LW-14758. I would like to get the correct one but could recalibrate the existing.

You could check the dip stick when you do your weight and balance - as aircraft will be in level flight.
 
I have always found the engine will 'find' it's own level. On mine if you fill to 8 quarts it goes down to about 7 and stays there - then about 1quart use over 45 hrs. If I keep filling it keeps going back to about 7. Same on my other aircraft the max is not always the best. Engine usually finds what it's happy with.
 
If you are doing aeros or heading off on a long trip may be worth filling up to max.  
 
Check engine manual. Mine lists the minimum - don't want to post qty here as cannot remember the exact figure. But do remember being quite suprised by how little it was.
 
Tim

I have my Superior engine manual in front of me now........
 
Oil sump capacity (as stated on dip stick ) 8 U.S. Quarts.
 
Now for the interesting bit!!! It states 'Minimum Safe Quantity in the sump' 2 U.S. Quarts. How about that hey! I seem to remember thinking it was not a lot!
 
This is for Superior IO-360, would Lycombing be any different?
 
Tim

My RV6 was a nose dragger with correctly spec'd XP O-320 engine. I changed it to a tail dragger filled up with oil in 1 quart increments and the dipstick was still fine so need to change.