Re: evinrude 85 hp
What model do you have? I don't think the 85 was ever made with a short shaft (15"). The long (20") shaft engine can be converted to an extra long (25") by inserting an extension in the leg and replacing the affected parts with XL shaft parts.
You might find the parts on eBay, or you can try
www.tcoutboard.com for used parts.
This sort of conversion is fairly common, both ways.