I have been a little concerned about my 460 since I put it back together. I had new pistons pressed onto new wrist pins on the stock rods, and the shop that did the machine work was not all that great. 4 of the 8 where so tight that I could not get them to rotate freely, and could not move them without using both hands. I took them back, and they seem to have fixed them mostly, to a point that I was not concerned. After I reassembled it, I was able to rotate the engine by hand, without a whole lot of difficulty, though it seemed tighter than I liked. I then mounted the heads, which had some nice Comp springs, new flat tappet lifters, new push rods, and now the engine is TIGHT. I really have to crank on this thing to rotate the engine. I use a generous amount of assembly lube putting this thing together, but it just seems like something is wrong. I checked all clearances before and durring assembly, nothing seemed amiss. Could it be the heavy duty springs in the valve train that is causing the hard rotation? also, with all the new parts, could it just be the need for break in? Any info would be great, hope someone can ease my mind. I would REALLY hate to have to tear this thing down again.