advice on purchasing correct scan tool

[buzzinhalfdozen]

Forgot to ask exactly how were you going to retard the cam using a scan tool? I'm unaware of a variable valve 5.7 being built in those years. Maybe you're talking about backing up the cam sensor angle? If so that info also should be displayed on most any scanner, however after adjustment you need to rev the engine above 1000 RPM for it to change the reading on the scanner. Good luck Joe