every manufacurer built a boat anchor at one time or another.i am ford and navistar all the way but you couldnt give me a 351m or 400m gas motor.i had an 84 f250 with a 300 6cyl and loved it 300,000+ miles until swapped up to my 92 f250 diesel and love it to.kinda off the subject but it is all opinion on which motor is a boat anchor or not,the cummins is not a boat anchor by any means,but that duramax, well i dont know , aluminum heads on a diesel,come on!