You guys need a bit of an edgumikation on EGTs, probe placement, and effective use of the information provided by such.
First of all, the probe should be placed half the collectors diameter in distance from the exhaust port. If you have 2" collectors, put the probe 1" from the exhaust port opening on the head.
Second, EGTs in abstract have no meaning. Saying "1515F is crispy lean" is wrong. Not because it couldn't be the case but, rather, because you don't know what the appropriate peak EGT is supposed to be at the torque peak on that engine. 1515F may actually be overly
rich on that setup.
People think that the leaner you go, the higher the EGT gets. This is incorrect. Peak EGT occurs at stoich - about 15:1. If you go richer than 15:1, EGT will drop and if you go leaner than 15:1 EGT will
also drop.
The only way to know what the correct EGTs are for a given vehicle is to measure them in conjunction with a wideband O2 sensor on a dyno.
What EGT is good for is a reference for where the engine made maximum torque at wide open throttle.
It is really the AFR that is important, not the EGT. Most engines will make maximum power at an AFR of between 11.8 and 13 to 1 however, the EGT may vary from 1250F to 1800F and is dependent on many factors.
What temperatures you internals can take is another matter.
Since aluminum melts at 1220 and alloy is significantly higher, you won't know until you melt something.
