A blaster piston on a 5mm longrod crank will be .040 or 1mm down in the bore a tdc. If you dont have a spacer plate it might be a longrod crank not a 4mm stroker. A piston .040 down will have real low cranking compresson.
Just wanted to say thanks for all the help. I have been reading a lot of post's where you have replied. Your answers are very indepth too a widerange of subjects.You are a asset too the HQ. Thanks again. ERIC