CAn anyone give me some insight as how to check my timing in these 97 454 mag MPI's.. The ECU was worked a little for a supossably little more agressive timing curve and rev limiter bumped to 5400.. Far as I know still set stock other than the ECU adjustment.. SOmeone told me it has to be above a certain rpm before you can check timing on an MPI engine..
I have delt with carb motors and MSD ign all my life but know nothing on this ECU stuff.

it's programmed in the ecu, whatever they put for a timing curve. call whoever tuned the ecm ask what rpm they brought max timing in at and how many degrees then verify with a timing light just like a carb'd motor