I picked up a complete explorer engine today and was wondering if the heads on this engine are any better than the stock heads on my 95 gt. From what I have read, these are gt40 heads. For what I paid for the engine, I couldn't even buy a new intake system. What size are the valves etc compared to the stock heads? Any suggestions on mods to these heads, I really don't want to drop the bucks for afr's. I am just looking to pickup the overall performance on the car.