Sounds like I have main bearings knocking?

[Bigshorty]

I just picked up a 93 5.7L 4x4 with 194k miles the only problem is there's a knock in the engine for about 3 sec after a cold start. Thinking of dropping the oil pan and just putting bearings in. I have a 350 from a "73" el camino should I build it and drop it in? I know it has a lot of miles but besides a little knock on start up it runs really good.

 

[Fleeingpepper]

It goes away after a few seconds? Leave it.

 

[97c1500]

it's carbon knock my truck does it for about 10 seconds in the morning nothing to worry about but if it really bothering you seafoam it and then take it for a hard drive it should help