300-6 is my daily driver, engine of choice. '91 F150 4X4 5-spd., longbed single cab. I paid $1000 for the truck 4 years ago. I think the previous owner ran the motor low on oil, because the crank and rods would rattle on start-up. It would run fine with decent oil pressure once it warmed up though. The odometer said 256,000, so I pulled the motor down, honed the bores, installed new rings on the old pistons, new rod and main bearings on the stock crank, new oil pump, new cam and lifters, new timing gears, had the head overhauled by a friend at his machine shop, had the flywheel surfaced and installed new clutch disc and pressure plate. I figure it should be good for another quarter million.