This morning used laser temperature Tool to measure heat on my '66 fhc. Found 600f on front head with 450f on adjacent header. While exhaust pipes were driver side 99 and low 80 on passenger side pipe ? Choke on to start and then off when engine warm. No coolant overheating. All three jets are even height and depth (when choke on).su tuning tool indicates identical idle sucking. Driver side pipe warm air to hand and even firing while passenger pipe rough firing and cold air to hand. Tach shoes idle at 1k, no spitting, revs nice. No smoke and no pipe spitting/oil.