[Engine] Converting a TBI Heads To Vortec Heads

[BLK1500]

I've Thinking of things to do to my truck, but I'm more focusing on my motor right now, the truck has been in our family since we got it at the dealership in Phx,AZ. It show around 480,000 miles, but that things been broken for two years now, and I don't know how much miliage is on it now. We never had top tear the motor down, doesn't smoke, I guess what i'm asking is can I get away with re-ring it and put a pair of vortec heads on with a intake on? If I can get away with it, what am I expecting to get for the motor (push rod size, lifters, rockers, etc???)