Help...20V valve probs..

["Steven Barnes" <sbarnes@acs.ucalgary.ca>]

Desparate for some advice here......

My 90Q20V had been parked for several days in temps between -10
ans -20 C, with no block heater.  On start-up, the engine
sounded like a diesel, and I let it idle till warm, hoping the
clatter would subside.  It didn't.  

The dealer (South Centre Fine Cars) has looked at it and says the
timing belt jumped, therefore the clatter was valves and pistons
interfering.  So far, not good, but not tooooo bad.

My question:  how much leak down (IF ANY) is acceptable.  What
would marginally seating valves do in the long run.  Does anyone
out there have a range of leak-down parameters, numbers i can use
now to decide to remove the head or just time things up and drive
on........

Also, the throttle pot was broken off.....I can't imagine that
that occurred in concert with the timing belt fiasco, but they say
the throttle body itself is damaged and will not accept the pot.
I haven't seen it yet, but I hope someone out there will say that I
have some less expensive options than buying a new or used (cross
fingers Shokan has one) throttle body.

Anyone not yet into their Christmas Holidays is requested to
reply!

TIA

Steve, Calgary Alberta
90 90Q20V......
87 5kTQ
86 5kTQW
56 AH 100-4