Hello all I have yet another oil question. I just purchased a 2004 FLHT with 23K on it. According to the original owner he had always used HD 360 oil and I am an Amsoil fan so I wanted to switch. Anybody have or heard of a problem or potential problem with switching oil types. Thanks in advance for any help or comments. I love this forum and find it very helpful. This is my first Harley and used advice in this forum to change rear brake pads yesterday. It has a stock TC88 and I was also wondering what some common upgrades. Currently the bike has a K&N air filter, Rush exhaust (a little loud for my taste) and that is about it. Thanks.