383 main bearing clearance question

[1970fury3]

Ok so I have a 1970 Plymouth fury with a 383 im in the middle of engine tear down. I plastigauged the main bearings and came out with .004 to .005. I’m only getting the engine running for temporary use and won’t be pushing it hard at all. So my question is how bad would it be to run those main bearings for 10/20k miles while I build an engine on the side for more power?

 

[Chryco Psycho]

with 20-50w oil & a high volume oil pump you should be ok , but for about the same $$ you could get a set of undersize brgs too depending if the brgs or crank is worn , typically the brgs will wear first as they are softer

 

[Racer Dave]

What he said. I allow up to .0035 on a race engine, so with heavier oil you should be fine for 10-20K.