went to vilas today to drop off the cam bearings, freeze plugs and pistons so it could get bored and found out my heads are cracked in 5 places. aparently not that uncommon. i have a set from a 86 but the valves on those are really small ( maybe 1/2) the size of the other tbi heads that are cracked. what heads should i look for or should i just use the ones i have with the smaller valves