is it worthit to upgrade my supra with stock turbo?

[Grandavi]

yes.. compression! Thats the one thing people forget about when redoing a head gasket (some people...). When you redo the head gasket, do the valves as well (stupid not to) and check your compression prior to starting. The pistons/rings/valves/head gasket all are facd with the same pressures throughout their lives so there is a bit of wear and give that takes place. When you redo the head, if your rings are weak, you'll have a problem. If you have valve issues .. they will be increased.

Its not a huge problem, but I would not ever (personally) pull the head off and not redo the valves.. especially with the amount of people I have talked to with the same problem as mine.. oil leaking past the valve seals while sitting and blue smoke on startup.

Because I have only had my car for 3 years (about 7-9000 kms since buying it) I had a professional do a leakdown and compression test on it so I had a very good idea where it was standing at present. That tells me what to expect out of it. So far.. I am lucky.. all seems to be rock solid other than the valve seals.