David, I don't know where you are located, but there is a trailer supply store in Anderson on 28 By-Pass. It is called Wiles Supplies?? He ordered a round 3" drop Axle for a travel trailer for me and it was reasonable. In fact it less than I thought it would be. If it is a common size he'll probally have it in stock. Mine was a odd ball. If you have a drop axle now and go with a straight, your boat is going to be higher. That will make it harder to get into and you'll have to back it further into the water to get it on and off the trailer. I have been in there in a couple of years, but the last time I was he had several 4" drops in there. I hope this helps. If you need a phone number or directions shoot me a message.