slipped my mind one of the most imprtant of all is the p90a head (one of the 2 turbo heads offered for the 280)
almost a necessity when turbo charging the 280 the other 44 head cracks easily when high boost is exposed (6 psi) with an intercooler you can run a slighly higher setting (approx 8-9.5) and with a much more efficient than stock turbo and an intercooler you can run as high as 12 with 93 and cool days (as long as the motor is up to snuf that is....)
sorry for failling to coment on that allthough thwere are p90's available the plentiful supply is getting fewer and fewer get them while there hot....