I have a vintage Bryant 350 MAV that is temperamental. The gas will not ignite unless the igniter is in a perfect position. What is the "exact" igniter replacement part for this unit? BTW, all the items have been checked professionally, gas flow (in and out), gas pressure, air flow, air pressure, safety switches, etc. The only item that has made a difference is the angle and height of the igniter. Unfortunately, the replacement unit seems to be an after market replacement. Any ideas?