Pistons need to come down with the crank, friction of rings in the bore, also the crank bearings are a close fit and need a little wiggle. I assume your working on a straight six. If it's a V8 the timing chain needs to be removed.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
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