I have a 350 suppose to be rebuilt about 5000 miles ago. Decided to tear into it to check it all over. Just found 2 lifters shot, and the last lobe on the cam shaft, completly smoth around. No more lobe. There is noticeable amount of build up too. Glad i only traded them stuf worth about $200 to me!!So now i decided to go with a 400. Anyone have ideas where to find one, reasonable priced? So now my plan for a bigger engine is put on hold.