I wanted to post this on the race board to get an opinion from some fellow engine builders who have some savy. I took apart a 440 block from a 68 Charger for a restoration. This car was one of the long time local hot rodders who has done some street racing back in the late 60's through early 70's. According to the previous owner, the motor was blown up and it took out the block. A 70 block was found and all of his components were installed in the new block. It is a 4 speed car so the crank was used with the correct hole in the crank. It was a average garage rebuild and not at a high performance machine shop I can tell for sure. Cheap pistons and bearings were used in this .030 rebuild. They must have lost one head bolt and found a Chevy replacement for it. It has a stock cam like a rebuilder would use. The thing I found most interesting is that all of the pistons had marks where both the intake and exhaust valves have kissed the pistons. Not very hard but marked on all pistons. I measured the lift on the cam and it was .417 which is stock. It had a stock nylon timing gear and it was sloppy loose. I can't remember taking a stock 68 440 HP motor apart. Did they have nylon gears or not? The pistons are cast flat tops and I did not measure the compression height but I bet they are not 70 six pack compression because they had not valve reliefs. Any guess as to what could have caused the piston nicks. My guess is over revs or a missed shift and really buzzing the motor. It looked like stock valve springs and I doubt that the rebuilder even thought about new springs. I guess a stock cam with wore out springs could float the valves enough to do this. I have and old SS racer bud who drove a 67 Chevy II with a 327 4 speed in SS and every time he missed a gear, he would bend all the vavles.What do you guys think.

68 would have the nylon gear, I had one when I was 18 that I spun it so tight it just shut off...no bangs nothing just shut off....five minutes later it fired up & ran fine...Apperently it pumped the lifters up & held the valves open...A few years later when I took it apart I found it had kissed all eight pistons two impressions each...didn't bend a single valve...I knew two other guys that did the same thing..

Two or three beers, one missed shift equals witness marks in the pisons Are the current pistons any where near the top of the block or are they way down, the reason I'm asking is to try and determine how hard the valves touched the pistons. Are any of the valves bent slightly or at all? If so I would replace all the pistons to avoid the possibly of cracks in the piston tops and skirts that you can't see, cast pistons can and will disentergrate(SP?) once they are cracked or fractured

I have not completely disassembled the engine because it looks to me that I will use a different rotating assembly. I was hoping to salvage the crank, but it is a .010-.020 shaft now and needs it again. The rods are mismatched as well. I have a complete 68 motor that I will use from a low mileage NYer that is std bore and crank. They make the best cores. You know the type, driven by a little old lady to church on Sunday motor.The new pilot bearings for the hub of the crank now make it easy to use the auto crank. Thanks on the responses, I kind of figured it was a few to many r's.