I have searched the web and the threads here and was wondering if anyone has any 'actual' experience using the bearing spacers by one company or the thick bearings by the other company to use a small journal crank such as 283 in a larger journal block such as a 350? Some say they work fine,some say the crank will run hot,,,,anyone actually using them that can give me first hand experience? I have been to 2 machine shops today and they tell me that the talk on the internet is just talk,no truth,as to which 283 blocks can be bored to 4". And only 1 shop in town does sonic testing and I could buy another block for the high price they want to sonic check. One machine shop owner with 30 yr's. experience said that 90% of these 283 blocks won't bore to 4" so a 350 block and thick bearings is sounding better,but do they last?