i own an f combine and i am very pleased with the performance of the 292 gas engine good luck on your purchase cannot help you on flex head wanting one myself but cannot locate
I also agree with the previous post. I hear that the diesel's are good engines too, but I've had experience with many 292 engines, and I have been beyond pleased with them!!!!!!!!!!! Also I'd stick with the standard shift instead of hydro, but it's up to you! Good luck! You'll like the F series I think.
I would either go with the four cylinder turbo or the six cylinder diesel. My neighbor has the gas and he wishes he had the diesel engine because they don't use near as much fuel as the gas. In the long run you will save money in the fuel cost between the gas and the diesel. But that is just my own opinion.
not to say they all aren't decent, but my experience with the diesels has been bad. The 4 cyl. models are imports that are hard and exp. to get parts for. Also, not high quality as far a diesels go( ie: cummins). The 292 gassers are by far the most reliable, BUT, they are also thirsty. You have to decide what you need. Hope this helps!