Since this is just a toy, why not flatten the head yourself. Get a 600mm by 600mm piece of plate glass about 12mm thick and some loose silicone carbide abrasive (120 grit). Make paste of the grit with oil and spread on the glass plate. Set the head on the glass and move it around in all direction using the full surface of the glass until it is flat and even. The weight of the head should help keep the pressure even during this process. My guss is you can remove greater than 0.1mm per hour.

By the way, what if field racing?

Dan

The only possible long-term solution is to flatten (machine) the surfaces of the head and the block. Nothing else will work.

--
Matt L. -- Cary, NC -- '91 740 wagon

Good luck with those cheap-o fixes. They never work...thats prolly why they are so cheap. I recomend taking the head off, having both the head and the block straight edge tested for warpage and milling accordingly. This took me (it was my first OHC car) around 8 hours to do and about $400 labor and parts. If you are racing it, higher compression could be an asset anyway. this will be a byproduct of the milling process. You can ignore volvo spec for milling the head, as it is super conservative. I believe they recomend no more than 11 thousanths be taken off (I did 18 and it is fine). I feel like it is unlikely that you warped the block as it is a big old chunk of iron, but nonetheless it needs to be checked. There always exists the chance of finding a cheap used motor. I found one for around the same amount that I spent on my car, but i had no way of transporting it and I wanted to learn a little about my brick too. Take my word for it...those liquid paneceas never do crap and you would be better off trying to plug that leak with the dollars that you would spend on those rip offs.