Just found this thread i did an injected 4.4 with holden flat top pistons .... i got piston slap you need to use genuine leyland dished pistons. Cost me lots of dollars to sort that one out the tuning guys swore it was mechanical and the engine builder swore it was tuning ... a guy in his 80's was at the tuning shop i was telling him about the issue, he laughed at me which i found insulting at the time but the old boy knew his stuff told me striaght off the bat i had holden pistons in the motor and also informed me they were flat tops ( then i stopped be insulted and listened ) . if i remember right the gudgeon pin height is slight lower on the holden pistons for carby engines it is fine but inject or worked motors it causes big issues. He use to race these engines in the 70's in speedway cars so after a few hours of chatting I was back to the engine builders and now i have a stump puller of a motor :D well 9 years ago anyway
