P0174 and coolant loss

I have a 1998 3.8 with 170K on it. I am getting a po174 code(no po171) and am using a small bit, about a qt/1000 miles, of antifreeze. I suspect either a compromised head gasket or, once again, the lower manifold gasket. Either way will seep coolant into #1 cyl. Does anyone know how I can tell-short of pulling it apart- which gasket is shot? Or maybe it is some thing altogether different. I am at the point of scrapping this thing. Anything and everything you can imagine going bad on a Windstar has happened to this one. Should have off loaded this pig a dozen years ago, but I'm just too stubborn. I tend to keep junk on the road way too long.

take a look at the plugs individually, that may provide you with a clue. You could also do a compression test if you have the tools. I'd certainly be doing an oil sample with blackstone labs and they'll undoubtedly shed some light on you problem. I have had similar problems with a different vehicle that was leaking coolant subtly and I ended up using some of the gasket repair gunk to the antifreeze. Solved the problem well. I'm generally not a big fan of the 'quick fix in a bottle' but it may be worth a try.