i just started on my 3rd gallion with this engine so it has about 2 and 1/4 through it. i will check the fuel tank tonight. seeing as it is not the one that i ran for the first two gallons of fuel through the engine. it didnt dawn on me untill after i read your guys post. but the engine was fine in my other car. duh!!!! lol. i am optamistic that is where the problem is. the clutch and bearing are fresh just changed them all out befor putting the engine on my crurent car. i will do some more digging tonight when i get home. check the tank and front bearing, and swap the tank out see what happens.