I didn't have to mess with swing arm pivot bolt holes on mine. Nice and snug, but yet still pivots freely with zero drag. I also cut the factory LTR450 oil tank tubes completely out of the way to clear an exhaust better and welded in gussets. It's not a hard conversion to do, especially if your not going to motocross it. You could just cut the original top rear shock mount off completely and build it from scratch once everything was mounted, but ride height and handling was key to me for MX. I just cut the right side of the upper shock mount off as close to the mounting tab as possible and did some reconstructive surgery on her. Now I can clear almost any carb no problem and never worry about it breaking either. There's a guy on youtube from france or australie, something like that, who built a YFZ/LT500R hybrid for motocross and has performed really well on it. I'll be running all long travel Fox Float/Laegars setup up front, Stock Swingarm/Walsh Linkage/Fox Podium single rate remote rezzie rear, 40mm Lectron, custom alluminum airbox etc etc etc. More pics to come when I get it rolling(1-3 days).