OK so some more info about my issue :
The issue only happens when held wide open throttle for lengthy periods , can either be say 2ND gear around 6500/7000rpm , or even just wife open in 3rd in a straight line around 5000rpm .
It completely cuts power for maybe 5 or so seconds. Like braaaaaaaaaaaaaaaa borrrrrrrrrrrrrr then takes off again .
I put a second hand walbro 255LPH fuel pump in
Re wired pump straight from battery through switches
Fitted a adjustable FPR
Still does it . There is another 4 guys I know of with the same issue , 1 fitted a MSD coil to see if that would fix it but it didn't .
My rotor button / cap is a bit shitty but it never miss fires or runs bad at all when driving normally.
Running out of ideas what it could be .
Cheers !