Thanks, when i get home tonight I will double check to see if my sprocket marks match up with my timing cover marks. The more I think about it the more I think this is the culprit. I was thinking timing advance would need to be adjusted to compensate for the increase in compression, but I was thinking more retarding would be the way to go not...advancement. I have a 72 pontiac 6.6 liter V8 that ran like garbage when i got it and when i gave it a lot more advance it really woke up. I then read that it only has 8.5:1 compression. I guess low compression means more advance and high compression means less advance? I guess this volvo starting at 9.5:1 and being milled .018 probably has 10.5:1 or even 11:1 compression now...which to a V8 guy seems extremely high for pump gas...I would think tons of retard would be in order....I hope the solution is as easy as adjusting the belt...thanks for the input.