fixed VANOS w/Beisan's...perfect..est drive... half way through blew head gasket??

[RobPatt]

THink I blew the headgasket.. PLEASE read 'cause I need help!

I bought the parts, tools and did the vanos seal, rattle, and intake cam diaphragm exactly as described over at Beisan.

Everything went like clockwork. It was rather easy, and fun... Again, take your time and follow the directions.. read them three times!

Went for the test drive.

Car started perfect, no check engine lights,.... just my same old instant start eager engine.

Drove really REALLY nice... silky smooth and steady power delivery.. subtle but noticeable.

Went 3 miles, THEN got on interstate... engine temp middle like always.. everything seems great except a hint more power and smoothness.
Kept the windows open to see if I could hear that vanos rattle... it was GONE!

4 miles on the interstate maxed at 85mph and hit rev limiter (auto).. car was perfect, like her old self just much smoother and more pull.
Get off at the exit ramp, loop around to get on the interstate and return home... the onramp she just lost power.... felt like she started missing.

Limped it home at 55mph... thinking the timing "slipped" or something cr azy.
Make it home (I'm 3 miles from the interstate)... pop the hood and there's coolant boiling in my spark plug wells.

AGAIN... temp needle in the middle. I stressed thinking I overtightened something and cracked the head.. except I didn't.
I was METICULOUS about not overtighetning... kept thinking the head is aluminium.. and most of the torque specs were pretty low.

So I"m guessing it's a blown head gasket? There's coolant on my oil dipstick... there's coolant in the spark plug wells.


Questions:
1. Did fixing the VANOS just cause me to blow the head gasket... or just a strange coincidence?
2. How much harder is a 24C DOHC motor than an old chevy V8 (w/o overhead cams?)
3. HOW do I clean out the lower portion of the block? and all the coolant hoses? just FLUSH FLUSH and FLUSH some more?
4. Should I get the head sent out or inspected or whatever?
5. Should I now get new valves, and opt for an M3 cam? ( i have the GM tranny that I think is only good for about 225Hp)
6. What else should I do?

I really don't have time for this... how many hours might a local BMW indy charge me ?

Thank you so much!