I ran 550s on a TD05 20g for quite a while without any issues. Best ET was 11.52 on that set up.
I switched to a TD06 20g and was still running the 550s (never got to do any fine tuning though - bad rings). Not sure what injectors I'm gonna put in during the rebuilt.
Regarding spool-up, I loved the TD05. To me it was perfect. It wasn't sluggish at all and not too quick either. Very controllable.
_________________________________________ 1997 Mitsubishi Eclipse Spyder GS-T 1995 Eagle Talon Esi 1990 Eagle Talon TSi AWD 1991 Mitsubishi Eclipse GSX 1991 Mitsubishi Eclipse GSX