there was a bit in one of the paerformance ford mags an month or so ago

about wossener pistons , aparently well known and and used in the the german touring car series , got a good plug

i dnt know anyone using them in a rst but there supposed to a good price and can be made specific to ur requirements ??

think it was bb tuining that stocks them ( big tuner of 5 gtt s )

give them a bell ??

worth a look