So, we all know you can use K-series main bearings in a B-series block. But what i'm wondering since I need a red main bearing can I use a red main bearing along with the rest k series? I need to mix and match them so its red on top and pink on bottom?

 

I dont see why not...
Ive used different colors of honda bearings to get the exact clearance I was shooting for and I've even ran aftermarket bearings on mains and OEM on rods on another build...

I dont think it really matters as long as your clearances are what they should be...

 

yes, had oem on mains and oem on rod 1-2 and acl on 3-4 crazy but worked out just fine.

 

yes..some ITR/CTR motors even come that way...sounds weird but true.