I know it has little to do with the stroker on this thread but just of interest since Im giving up on my motorbike head as its too difficult on the CA, a friend has fitted the smaller B6 1.6 head onto a datsun/nissan A15 pushrod engine and working at treat after some careful engineering. I know many will say why not just go the CA head but just because I can i wanted to see the difference between a Mazda B6 (1.6) and BP (1.8) head and got the 2 gaskets lining up to find the 1.8 BP one was much longer than the 1.6 then since I had the CA20 block laying around the other day while stuffing around with these steel headgaskets, I couldnt help myself to try it on the CA20 block and by a crazy co-incidence it almost all lines up, water spot on, oil drainage almost a breeze and oil feed to the head is only 5mm away! That means those after a rare four port can fit a Mazda BP head with a little work that equals the 4 port CA head but slightly better port shapes from factory, solid lifters for factory 99 post heads and heaps of aftermarket parts that a CA owner can only dream of not to mention crazy variety of different rocker covers available.
Its crazy but at least theres an option for something totally different yet somewhat cool. Carry on my crazy spiel has finished for now