Well, my suspicions have been confirmed... I have a burnt valve in #1 cylinder.
I have two questions....
Is there a drawback to putting a 194 head on my 250 (while the 250 head is being built... may take a while and I need the car drivable)
I've never read spark plugs on a turbo engine... they pretty much all are caked with white. N/A engine, I would be looking at the head gasket or cracks in the head. Does this differ on a turbo engine?

Sounds lean. Mixture is mixture, at least from my experience. Even my blown motor still liked a little wheat color to make it live.

It is plenty rich under boost! I had imagined, too rich... my a/f meter is not installed yet.
Thinking on it a bit... with all the plugs looking pretty much the same, perhaps the gas? I tend to use the same fuel as much as possible. Also, I know the rings are weak. I guess I will be able to investigate a bit further once the head is off.

Not sure how much compression you have now with your boosted 250, but the 194 head with jump it up even more. Make sure you are running the correct fuel for the DCR you are currently running, if not, more compression will only make it worse. But no, there is nothing wrong with running one on there.

As a safety because I have no timing retard, I run 91 octane as a minimum. I will always seek out the 94 octane!
I will install my a/f meter to ensure my ratio is correct. The way it runs now... under boost it is pumping out a decent amount of greyish smoke.

This engine was a roll of the dice... I knew nothing of it but the price was good. I have enough blow by that it pushed the front oil pan seal out. Now, I've venter the crankcase and that has helped a great deal! Oh well, it is a temporary engine while the other is being built.

And how about a 292 head?

[quote=dodgycanuck]It is plenty rich under boost! I had imagined, too rich... my a/f meter is not installed yet.
Thinking on it a bit... with all the plugs looking pretty much the same, perhaps the gas? I tend to use the same fuel as much as possible. Also, I know the rings are weak. I guess I will be able to investigate a bit further once the head is off. [/quote

Make sure it doesn't lean out too much in cruise or part throttle. Unless it's a dedicated drag car, you're spending a lot more time at part throttle and in cruise mode than under acceleration. If it leans out too much at part throttle a valve can burn because it isn't getting cooled by fuel enrichment.