From an Aussie, get the whole 250 crossflow alloy head engine, this is a far better proposition than trying to fit the head to the pre crossflow block. We do have 200ci crossies, I have one or two, but if your going to stick it in a bronco, torque is king and the 250 will be far better. Crossflows did come as EFI setups with Bosch injection, Id get one if you are intending to go that way. The crossflow head will allow the 250 to rev better than any of the log heads and possibly even a 2v headed 250. Yes there is a bellhousing issue to be dealt with. Why use a slushie, use the manual trans. You could go for the 4litre SOHC six, which is better again, they come EFI stock, these have as much power as a carby 302, again bellhousing issues. If you do decide to go crossie then get the EFI setup, the stock exhaust manifold is OK on the stocker engines.