Trim baffle top to upper cowl with or without propeller mounted?

Title says it all?

Cowl halves was fitted by someone else. Fitted baffles without prop or starter ringgear. Now that I am at the point of trimming the top of baffles with the paper clip method. Do I need the weight of the propellor so that the engine hangs as it would with that extra weight? Or will a running engine with a propellor generating enought thrust 'lift up' on the engine mount in any case?

Regards
Pi

Ok not many responses. Some background, it is a io-360-a1b6 will be a CS prop estimate at 67lbs. Not a lot of space under that cowl.

If you don't want to hang the prop yet, just hang close to its weight off the crankshaft.
That would get you close enough to simulate it. I doubt it will sag more than an 1/8 inch more than without that weight and for baffles it's probably not that critical but it's your build and your call.