header to front tire clearance

So I've got this bike that I like to call "Frankenberg". It's a 2003 vintage frame with suspension from a 2000 FX600E that I used to own. Got in a head-on collision on the FX and bent the frame at the steering head, hence the odd collection of parts. Clearly the FX engine wouldn't fit the '03 frame so I scavenged the FE501 engine from my Brother's '95 non-e-start bike when he no longer had any interest in the bike and assembled Frankenberg when I found the '03 frame on ebay. Had a Big Gun exhaust on it for a long time but didn't like the excessive noise from that can so I pieced together an exhaust using the '95 header pipes and a muffler from about '99, or '00 (not sure).

I seem to recall this combination rubbing between the header and the front tire on big hits but it wasn't enough of a big deal for me to really worry about.

Then the 501 engine let go. Sounded like rocks in the engine. I haven't torn into the engine to diagnose because I picked up a '94 FE600 parts bike and swapped that engine into the bike. I had a set of header pipes for a pre-2000 600 got the bike going again.

So, to recap, frame is 2003, suspension (triple clamps, forks, front wheel) are from the 2000 and headers are from probably '96 or '97 600cc.

I was riding over the weekend at Tahoe, landed from a big jump and the front tire hit the header so bad that it almost tossed me off the front of the bike.

Now that I've explained my long-winded back story...
1. I understand that Husaberg was in the habit of changing the steering head angle. One change was somewhere in the 2003, 2004, 2005 era and they went from a shallower angle to a steeper one for better turning, right?
2. Were there any other changes to the steering head angle? Maybe late 90's vs early 2000's?
3. I know that there was a change in the exhaust around 2004/2005 to fix header/front tire rubbing but, unless I'm mistaken, the 2001-2008 exhausts don't fit the pre-2001 engines.
4. Were there any issues with header to front tire clearance on the pre-2001 bikes where if I find the right set of headers, I'll get better clearance? (Wish I had kept the headers from the 2000 FX600 as they'd probably be the answer)
5. Has anyone adapted a later exhaust (say, 2005 to 2008) to fit a pre-2001 engine? If so, what would be the best to look for? I'm assuming a 550 or a 650 would have somewhat similar cylinder height so everything would line up the best. What about tube diameter?
6. What about triple clamp offset? What was stock for the 2000? Maybe I can get a set of clamps with more offset to at least help the situation?

Thoughts?

Here's my latest favorite pic just for fun.

Good info Taffy, thanks! I would, however, need the headers for a 2000 with the 600 engine since my 501 engine is no longer in this bike.

So, assuming that the location of the steering head remained the same, having the '03 frame in my bike actually helps this situation as it gains 1.5 degrees of clearance to the header pipe. I'm also using the Goldentyre GT216AA fatty tire which doesn't help as it's a huge tire. However, it's also some of the best front end traction I've ever experienced in a tire and I don't want to give it up.

Well, I guess that I'll keep my eyes open for a later 650 exhaust and break into some welder fun.