95BurbanAZ

Hey guys, i just joined this site because i was having some issues and i had been on another forum but no one really seemed too technical so i didnt get anywhere with questions but here is the list of whats happened with my cursed suburban lol. Well first i bought the truck from a family friend i had seen him driving it as a daily driver for years then he let it sit for a while and didnt have room for it anymore so he sold it to me. Before he let it sit it ran great and now after it runs horribly, it just kept sputtering when u gave it gas and at stops it would die and sometimes not want to start right back up, i tried to clean out the fuel system and change the injectors then something happened with the regulator and it filled a cylinder with fuel and hydrolocked the engine but it wasnt running or anything it was just hydrolocked when i went back out, i thought it was the started at first so i changed that, then realized the engine wouldnt turn over so i pulled the plugs and a cylinder was full of fuel, so i bought new pluts and got a throttle body from a friends buick roadmaster wagon that was running and put it on, i also changed the fuel filter, and the O2 sensor, along with the throttle body and the starter and it still doing the exact same thing, im not sure what else i should really check, any ideas? sorry for the long post and so u know its a 1995 suburban k1500 LS with the TBI 350