eibach springs and shocks
and polly bushes sort the handing out

if not eibach use koni adjs

as for chip
i would use unichip
blue fin has been used on the st220's to

i have seen a cosworth grp a filter on one
which made 242bhp on the rollers no other mods

for more power gains
need ss exhaust blueflame or mongoose and milltek are very good
and got good results
remove the pre cats and have a highflow main cat fitted

should be good for 260bhp with that
also can get hold of a mustang tb from the states to which will also help


there was a st220 in fast ford a while back which was pumping out 293bhp

that had exhaust,filter,pre cats removed,custom y-pipe, msds headers from states and a chip