The only real way to tell is to measure it (with calipers) and compare it to the sizes in the back of the sealock manual. There was a poster on PB stating he was spinning a double A to 6200 with a blown small block. Come to find out in other posts he had it cut down to a "B".
T.J.
This is correct information ! IF the exit blades exceed the large and small diameters It probably is a "AA" and theres nothing wrong with that depending on the application (boat HP etc ) , you (we) can alway "cut" a large Impy smaller but can't enlarge a small one . We like AA's for big Grunt motors , Blower and Turbo stuff and in BIG boats My RR Miller has a double A and has an enormous hole shot Almost every Bronze or Stainless I sell starts as an "AA" and is "cut/tune to fit"
pss "Factiod" although not likely the case with your boat lots of late model (90's) bigger boats were sent out with AAs to get thier fuel consumption ratings up closer to the IO's
