i have an 89 D-50 with the 2.0 and i think the motor code is 4G6X Sirius or 4g52 my searches bring up both codes.... well to the point i dont really wanna replace the motor i would rather rebuild it and get about 150-200 HP outta it. If someone could point me to a company or website that can help me or tell me which engine code is right i would really appreciate it. If and has any wallet friendly swaps that they would suggest as wel to increase hp i would like that as well. Thanks.