With all this in Loonies, I guess the whole bill would be around $1000 US, so it doesn't sound too bad.

Have you done the t-chain on your W126 recently? I'm surmising that your car is a V-8 like mine, since you talk about 2 rebuilt heads on your car and W126's never had a V-6.

If you don't know when the t-chain was last done on your car, seriously consider having it done. My dad and I found this out the hard way....read "Bad news...please advise".

-Sam