I don't feel confident about shipping I want to sell these 3.7 but I am not confident about shipping they are so large if I don't sell on AudiogoN I must go to dealer and sell at big loss. Does anyone have any experience shipping these 125 pound 3.7 speakers.

Try listing as local sale/pickup only...that's how I sold mine. Unless you live in the desert...there's likely someone within driving distance that might be interested.
I have shipped many of the larger Maggies and have always used Old Dominion Freight Lines.

That's the same company that Magnepan uses and they know exactly how to ship these speakers.

I think that they still give a discount if you ask and say that you are shipping Magnepan speakers.
It can be nerve-wracking, but shipping isn't usually an issue. How do you think they get to the dealers in the first place?

I used AAA Cooper, as their terminal was closest to home. The old 2.2/R went out to Minnesota for refurbishing and back home again. Even though there was a boot print on the box (yikes!), all was well inside.

Just make sure to pack them correctly (!) and insure for the full value, as you would for any sensitive components.
1. local pickup is always best

2. I'd book an air freight with cargo airlines and make buyer pick up the freight from the airport. I used often SouthWest cargo.

3. Note that if you're not selling locally you potentially loose more than 20% total if not more from the sale price.

I think Magnepan's biggest failing is not adding a couple hundred bucks to these somewhat fragile speakers and crating the pair.......

They send multiple pairs to dealers stacked on a pallet, but the dealer always removes them from the pallet if he ship UPS and then UPS turns them into abstract art.......

I speak from experience:

My advice to you:

If someone wants you to ship them, have someone build a crate for the pair with styro on all sides, and tell the buyer that's the only way you'll do it.......shipping them UPS or freight in the standard cartons, which are nothing more than a thin covering for the speakers will result in about a 50% chance of them arriving undamaged.......

Spend the extra money........have a crate built......there are shipping
co's in every major city that can do this for a couple hundred bucks....
Keep in mind one little thing - if they get damaged during shipping you will most likely take the blame.  
Thank you every one!!