cracked heads

[motofool23]

both of my heads are cracked and i want to put aluminum heads. i have a 91 explorer, and i want to know when the first year they put stock aluminum heads cause i want to put those on. and if they are even able to be used. thanx

 

[CDW6212R]

I do not know about aluminum versus cast iron OHV heads. I understand that there is little difference between the first and last OHV, in power.

There is a huge difference in power and efficiency between the OHV 4.0, and the SOHC 4.0. If you really want an improvement, why not scrap the stock engine, and find a donor vehicle to pull the later engine, PCM, and wiring harness from? Good luck,