Help with engine
My son has a 1991 Chevrolet silver-ado with a 350 vortech engine ( i am a mother and don't know anything about vehicles LOL) I bought his truck from a man who let it sit up about 5 years, when we first got the truck we put a new alternator, battery, spark plugs and wires and a new fuel pump on it. The truck ran fine for about 2 months and then one day on his way home from work. He turned off the interstate and it died. He finally made it home and I took it to a mechanic who said his number 1 and number 8 cylinders are not firing and he needs a new engine. The truck does not smoke and runs fine until it gets hot then it acts like it wants to shake when you put it in gear. My ? is does anyone know anything about this or if this has happened to them or is the mechanic right and he need a new engine? What should I do? My son is only 17 and knows nothing about cars either so i'm stumped as do i put money in this or just give up and try and buy something else.