OK so first off, thanks to the guys who showed me where to get a service manual for my goodwrench 350. Like I said before I was going to take my heads off, have them rebuilt, and put them back on myself (with the help of that manual of course). Again, this is the first engine work I've done EVER, but I figured it was pretty straight forward. But I've heard from more than one person that "If you rebuild the top end of the engine without rebuilding the lower end, then that could create more problems and you will risk having the bottom end going out and needing repair". If that is true then wouldn't I be better off replacing the engine all together or is that something I should take with a grain of salt. The engine is about 3 years old, the mechanics I had look at it all said that it was in great condition minus one valve and valve spring that they said needed to be replaced along with whatevers under all of that so they insisted that I replace both heads to be safe and they all know thier engines but they never said anything about the lower end of anything and for the job they are asking way too much so I said Ill do it on my own, with help. So if possible could someone elaborate what was meant by "the lower end could go out" and if so how could I find out if that is the case. Thanks and as you all can tell, I'm still learning about all of this so a lot doesn't make sense to me yet. thanks again.