Checking for head gasket leak

I might have a head gasket leak (milky looking crap in oil and out of breather tube I just changed T-chain and water pump so ther is a small chance that water is getting in the oil from those gaskets there is no water leak around T-chain cover or water pump I used a small amount of RTV gasket maker on all gasket surfaces and everything is tight so I am skeptical that there is a leak but I am going to R&R these gaskets again to make sure before I pull the heads off. This '87 GT has been sitting for the last 10 yrs in a garage I have only had it on the road for about a month so head gaskets may have been bad all along. Block testing fluid seems to be the way to go to test for bad Head gaskets i was wondering if I can just mix coolant with the block test fluid in a clear jar or should I get the whole block test kit. What do you guys think! Thanks for the info

It is carbed with a wieand stealth, electric fans, BBK H-pipe.