Main Bearings

Getting ready to put together the lt1 and before I put the crank and bearings in should I sand/prep the cap and block at all? I had the block tanked but did not line bore because its the same caps. But after looking at the caps they seem to have some black 'skid' marks on them and also the recess part on some are full of for lack of a better word gunk even after tanking. Any suggestion this is the first motor I am putting together.

Thanks
Jason

You would only want to "adjust" the caps before you have the block line honed which is the first operation that would happen before the bore/hone/decking....

If anything you can use a scotchbrite pad with WD-40 to clean the caps prior to assembly but not much more or you will screw up the round bore.

Bret