Your arm looks good and SOLID
With a WIDE 360 you want the tire to look like the wide part....not the width of the arm it self. Ive seen these arms before and they dont look right on a BUSA with 360s.
Here look at the Bacardi Busa...its tucked 360 looks good on 8 over arm..this is very good pic of 360 tucked in busa tail. Look how everything is close by the chain/ arm/ and tire...thats how its to be. BUT the kit in the link, bet the arm is FAR away WIDE for the kit.