Originally Posted by Paolo M

Wrong, it does not run hotter. It read a higher temp because your temp probe is closer to the glow plug. Actually the lower heads have an extra fin.

Myself and some others Factory Novarossi drivers have tested this head for both sedan and 1/8 scale since the last summer. There is absolutely no problem with reliability, temp and performance of the engine. We even use this heads in Houston, last summer in the sedans!!

The BIG advantage is the lower CG. The Head of the engine is a heavy part of the car that sits high (after the body shell, of course).
By Lowering this one, the handling of the car improves a lot.