Because of low compression on sixth cylinder I am going to rebuilt whole head. Toyota parts like valves, gaskets, bolts are very expensive. I am thinking about buying tuning parts instead of original from Toyota. Do you have any experience, idea? What should I buy and where? What are the prices?
I will change piston rings (by the way) - what and where should I buy? original rings from Toyota or...?
I am thinking also about head modification - polishing and more... Is there a sense to do it in twin turbo engine? What to do? What power increase could I expect?
Thank you very much in advance...

I will change piston rings (by the way) - what and where should I buy? original rings from Toyota or...?
I am thinking also about head modification - polishing and more... Is there a sense to do it in twin turbo engine? What to do? What power increase could I expect?
Thank you very much in advance...