Thanks to all for the replies. Pretty sure the engine is original as the pistons are marked CANADA. Haven't found a way to decode the stamped engine vin number, doesn't match the US engine vins. Started digging through the Forums the past few nights (instead of sleeping) and found lots of good info on the old 235's. Local machine shop price for rebuild less head work was over $2500 so I am trying to lessen the cost. I haven't messed with old Chevy 6's since the early 70's when I had a '50 5-window 1/2 ton (which I sold years ago and regretted every day since). So now with restoring the '53 I am trying to relive my wasted youth.