First of all you need a toyotool from toyotool.com. Have one for sale on 300zxclub site. Secondly I am quite sure that additional machining must be done on the heads in front of the lifter pockets to prevent the JWT cam lobes from interference with the head it'self. Learned this just recently after getting back my newly rebuilt engine. I belive this is also why you can't just buy Z1 cams. They will only sell them in their head packages because they have to perform the machining otherwise they interfere with casting.
:I've installed the 400 and 500 cams and have them on my car. :Had the valve work done first (valve springs not intalled) brought them back and finished a mild port then installed JWT springs keepers retainers. The problem isn't installing them it's getting the right valve spring compressor.
