I put a 200 in my 62 Ranchero replacing tired 170. never happy with idle or overall running.. If I got it to idle decent it would not pull mid range well. Installed a Pertronix and it ran a bit better. Tried several 1100 carbs. Bought a China copy cat of 1100 and it actually idled pretty well but still not happy with other ranges. Got a A-Team by Southwest Performance HEI and rewired it for 12v not the 9v delivered to old coil wire. Really ran well in around town driving but still acts like a miss at high range of motor. Doesn't ping or knock. Idles great. Just has thie feeling of a miss at high range before shifting gear, Reminds me of points motor with points closing up. HEI had allen wrench in box marked for "advance adjustment/" but no instructions Does the surging/miss sy upper end of rev's sound like I need to advance the timing? Never adjusted HEI thru the hex at end of HEI Thanks in advance