Hi Madjack, Jim, and GPW,
Thanks for your replies. I guess what I'll do as a double-check on my measurements, is to wait until the chassis is welded and the wheels are on before I finally decide how much overhang to leave with the fenders that I have. Being a beginner mechanic, I can't quite visualize how much space the spindle (swing arm?) will take as it spins near the chassis.
Once again, thanks for your help. I can't do this build without you.