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assembling con rods

Busy building a 4 bolt main 351C. Crank has been machined to -20 on both mains and rod journals. Using Clevite bearings on both and the mains bolted up perfect.

However we have some issues with the stock rods. New ARP con rod bolts fitted by the machine shop.

When we torqued up the caps on the rods (40 to 45 ft/lb) 4 of the rods are so tight we cant move them. Bearings are correct. Undid them again and removed all the rods/pistons from the bores.

Bolted them onto the crank again individually without fitting into the bores, 4 of the pistons are still tight so they will definitely be going back to the machine shop.

However the issue is with the other 4 rods that seemed to be OK. When torqued on the journal should there be any sideways play, in other words, if we hold the piston upright then rock it side to side should there be any play at all. Obviously it will slide sideways on the journal but holding the piston at the top and rocking it side to side should there be any play at the big end/bearing end.

I read one of Georges stickys about having the big ends re sized after fitting new rod bolts, whats the reason for that.

I would hope the machine shop would have done that as they are usually very good. However I am not confident now of fitting any of these rods. Any suggestions

cheers
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