Toyota Repair: Reason For Concern, head gasket failure, hydrocarbon emissions

Question
'92 Corolla/4afe/150K. About 2-3 years ago, I noticed that I get about 1
teaspoon of frothy (oil I assume) brownish foam under the radiator cap. The
coolant is clean, and none every migrates to the overflow. I flushed the
coolant last year-it looked brand new. But, the small amount still slowly
builds up. The engine has never been overheated.

The car runs great/doesn't use oil (heck, it is nice and clear as well when I
change it). Does this sound like impending head-gasket failure, or just a
small oddity of an older car?

Also, I will soon have to change the lower control arms due to a worn bushing
. Will the car need to be realigned as part of the repair?  I used to do all the
repair work myself, but now, I just let the dealer do the harder stuff :-) They
gave a rough estimate for parts/labor, but I don't know if they left out the
alignment.

Thanks

Answer
Probably nothing to be concerned about but I still would recommend having the dealer do a simple test to see if the headgasket is having a small leak which may soon become larger, the most reliable test is to use the emission control machine that detects hydrocarbon emissions in the coolant, they should know how to do this. Anytime that suspension components are replaced an alignment should be done.