F150online Forums - Possible main bearings going out/low oil pressure

I have a 2000 F-150 XLT 5.4L V8. I started having problems cranking it about 5 months about. At first it was intermittent, once in a blue moon. Now it's ALL the time. I thought it was maybe clogged fuel injectors, but it kept getting worse. It would sometimes not want to crank in the mornings or evenings after sitting a while. Is like it's not getting enough gas or some time of pressuer, not the starter or alternator. Also, coincidentally, there’s been a knocking/loud ticking occurring. Started very quietly but has gotten much, MUCH worse over the past 3-4 weeks. Another reason I thought it was the fuel pump was because eventually, be it a couple of minutes are 30 minutes, something, not sure what, kicks in and then it revs up to the proper idle RPM's and runs fine; however at this time the knocking starts. I can crank it, but ONLY if I hold down the gas pedal, but if it sits a long while and I go back it will usually crank on it's own. If I let up and my rpm’s get down near 1000 it dies. Like not enough gas being pumped in. I have not had any warning lights come on either.

Ok, that long novel being said (just trying to cover my bases), my mechanic, who is we trusted and reputable, says it my engine is having oil pressure issues and the lower end is going out. He says that my main bearings are get real bad. He has heard of this happening over the past year in several other Ford's with similar engines. First, any thoughts on his deduction of my situation? Secondly, has anyone heard of any recalls for similar issues? He says he heard of one for the fuel intake.