How bad is this 12a blown?
 

So I have a 84 GS stting in my shop.
It has a pinapple racing street ported motor, rb exhaust, no emissions, and now a new radiator. When the old one went, it took the seals with it.
I drained the radiator and got a 50/50 oil/antifreeze mix. Normaly when the coolant seals go I find water in the housings, and I did, a very small amount, but damn this is ALOT of oil and water mixed. This normal? I am crossing my fingers that a motor with less then 11k on all new parts isnt warped.

I think your dowel pin seals are leaking... the higher pressure oil leaks into the lower pressure coolant jackets. I got oil in my coolant when I cracked my rear cast plate.

I'd recommend at least a basic rebuild. Just buy the soft seal kit, tear it apart, check everything and reassemble it. With so few km on it, hopefully it'll all still be good.

Jon

Thats what I am planning/hoping :).

Whats the best place to get a soft seals kit?

I get gastek kits from Mazdatrix. They're around $100. It should be all you need on such a recent rebuild.