The answer to the question "Is it factory?" depends on where you live!
The Electra-X with its own distinctive tinware and disk front brake appeared in the UK first in 2004 and was then imported into Europe and the USA.
But customers in the USA were ALSO offered what was called the AVL Classic Bullet (never marketed in Europe), this was the stock Bullet running gear, fuel tank, tool boxes, drum brake forks, etc, but with the 500 lean burn/Electra-X engine and gearbox fitted at the factory. If you live in the USA (PopSmoke sounds American!) then that could well be what you have. There was also the deluxe version with more chrome bling. These were probably the last export Bullets anywhere before the EFI/UCE models took over completely.
Just for the record here's a picture of the limited edition A500 AVL Machismo, officially only sold in India, note this has a disk brake up front and the 350 Bullet rear mudguard/fender.
Interchangeability of the AVL and traditional Bullet engines means that your bike might possibly have had an unofficial engine swap by a previous owner or their local dealer, but if you're in the USA I suspect you have a factory model.
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Thank you very much for the answers. 500 bullet with an Electra motor/ 
Thats it iron head and all. I think it will be stock piston,too much worry a 535. trouble to make and may be to much for the rest of the bike.