My 80 had HEI, my 89 doesn\'t? I thought HEI was better, so why did they go back to the other style (points?)? Another question, would there be a big difference in power going from the exhaust maniflods to headers without changing anything else on the engine, or just a tbi spacer? I don't have a smog pump or those lines coming out of my manifolds like my 80 did, just the O2 sensor. Would I need to get headers with the o2 sensor or should the sensor go in the exhaust pipe? Thanks.