Have a buddy who recently blew a head gasket on his 91 mr2 at 169K miles. From what I know and i'll check out the motor in person soon, the T-belt and waterpump were replaced 1-2K miles before the engine blew. Im thinking of buying it from him for really cheap, replacing the HG with something like a TRD or equivalent so I can run a little more than stock boost and not worry. I need to know if anyone knows if there is any difference in the motors between a 91 MR2 turbo and my 90 ST185 motor?? Thanks for any info, IIRC they should be the same in every way. Just worried about compression, or something electronic that is different as the ST185 has a 6700rpm redline and the mr2 starts at 7000.