Promar does not want to stand behind their engines. I have had rear main seal problems with one of their rebuilt engines and they will only pay some money for the repairs in which "they" recommended. I had to put up all the money up front and now they want me to pull the engine and send it back again mostly at my expense. The damn thing leaked like a sive right from the beginning. It's only been in the truck for a week. Seal changed twice. Promar told the mechanic to pull the tranny and flywheel to see if it could be something else. It wasn't. The mechanic does have over thirty years experience and builds race engines for Ford guys in the area. I have some confidence in the guy. Now promar said he should have used a borescope to look instead of pulling the tranny, REALLY? Then why did you tell him to pull the transmission? Promar!