I got my stroked 416 and A904 transmission rebuilt back last week. The builder also helped me purchased a TCI 10" Super Street Fighter converter that is supposed to be rated 3-3.5k stall. Engine dyno 528 ft-lb at 4400 RPM and 491 HP at 5500 RPM. Don't have the details on the trans but it is beefed up for 600 HP. I need a flexplate to marry these together. I have a 6 bolt forged crank, internally balanced (7/16" bolts) and the 10" converter has 5/16" bolt tabs. According to TCI, they do not have a SFI rated flexplate that meet my needs. Unless I drill and tap the 5/16" to 7/16" myself. TCI does have the 145600 flexplate which looks like the stock flexplate and it is not SFI rated. However, it is supposed to be made with forged steel.
Question, how important it is to get a SFI rated flexplate? Car will be street driven. I will nail the gas pedal once a while and might go to the drag strip once a year but no competition racing on the track. Will the 145600 live or am I looking for trouble? I rather not drill and tap my brand new converter since I don't have a drill press to hold everything steady.