Hi Dave,

If the instructions provided you with a firewall-to-thrustwasher measurement, and this is where you set the engine position, then you should assume the cowl is too deep. This can be expected from kits that are not exact scale.

As for the cooling, if you have adequate air intake on the front of the cowl, (I'd toss that conical spinner shown in the pic and use a Higley's hubnut type... Closer to scale) and enough area for the air to exit the cowl, then just cut the cowl enough to access the glowplug. Or use a remote plug adapter and keep the cowl intact if possible.

Good luck.

Dave