D I've talked to one of the people who engineered an A-series block with E -Series Head: What i do remember is that they built up the water a passages on the back of the block so they mated up with the head, also the timing cover was modded for the belt drive to keep oil splashing out obviously. The one aspect that we don't always talk about is as far as the USA modded motors they were in single seat sports racers which have room for the rearward facing distributors or crank fire ignition. I'll try and email to see if there are any engineering drawings to be had.

Now as far as AY/AZ, boy a twin cam head would be the thing to have but as mentioned our cars are lower down the food chain.................for the bucks to have twin cam heads made you could stick in a Cosworth BDA or FWA etc.

Tom