In looking at the new designs coming out, I've seen some with the fairlead centered in the bumper and others with it offset. Why the difference?

For instance, the Shrockworks stubby is offset to the driver's side a bit:



While the LoD is centered:

 

The offset ones are to accommodate the powerplant since the powerplant is too wide to fit btw the rails and have the drum centered. I'm going with the Lod bumper. When I ordered it they said they will cut the hole for the fairlead so it is centerd on the drum, which they said will make it offset to the drivers side about 1"
I think the Lod in the pic is pre powerplant..

 

On our bumper, the winch is where it has to be to fit b/t the frame rails. We centered the fairlead on the winch spool....like it should be. It doesnt look like the fairlead is lined up with the winch spool in that other pic.

 

I agree, I would rather have the fairlead centered on the drum, even if its off center a little on the bumper.

 

Either bumper/winch will pull you out reguardless. One isn't better than the other. Its just personal preference. The winch and fairlead is slightly off center. No big deal.

 

If the fairlead isn't centered, what problems can occur?

Do various winches sit differently between the rails, or are they all the same?

 

Nothing as long it is bolted in correctly and firm. Synthetic line winches and regular winch cables use different fairleads... as long as they are correct you wont have a problem with either.