Thanks Retro man great stuff👍🏻Mine is a 103 now but was originally a 88. It doesn’t have manual compression releases fitted running a corrected compression of 9.8,cylinder pressures at 180 psi. However it does suffer from starter buck infrequently. I have a dtt ignition and speedzter has explained to me that I need the software to program in a delay on startup to help with this. Now back to my original concern in topic,if I change over to synthetic from mineral will I need to flush all the old oil out by double changing or won’t it be a problem?