original 12A with 92000 plus original miles and compression still within acceptable factory specs wit ORIG apex and block seals, 600 cfm holley,pacesetter header and orig waterpump, the lil 12A held up pretty good , but i pushed her a bit too far ,I blew the front rotor spraying 100 shot NOS got half way thru 3rd gear windup on 1/8 and blew motor drove it home on the second rotor and made it with no problem. show me a piston engine that can do THAT! once they blow they're GONE ROTOR's RULE BABY !