heya, ive been trying to find spec for the rob bearings..and cant find any specs for them...im after the tolerance
allowed in them as ive used a plasticguage and they came out with 0.005
or if anyone has some other info yo help me sort out what size i need that would be great

By the book and for the 1957 V8’s, rod bearing clearance can fall anywhere between 0.0008”-0.0027” while main bearing clearance can fall between 0.0006”-0.0032".  My own preference is 0.0015"-0.0025 for the rods and 0.002"-0.0035" for the mains.  I will suggest using a micrometer to check rod and main bearing clearances though.

Lorena, Texas (South of Waco)

ahh ok sweet...cheers for the info

ok so if it falls between 0.0015"-0.002 do you use  a .010  sized bearing or standard 

You would have to measure the crank journals. If the clearance is .005, which is too much, you would have the crank machined, reducing its diameter. Then you would need the corresponding oversize bearing. You're aiming to have the .0015 to .0025  clearance....whether it's a standard unground crank, or a machined crank .010, .020,  or .030 oversize.  For example; if the crank was scored and you needed to remove .030 material to clean it up, then you would use .030 oversize bearings, but you would still require the same clearance ....  .0015 to .0025  .   These tolerances are determined by the crank grinder. Hope this helps.            Barry L