I have a lycoming O-360 A1A installed in a Thorp T-18. Recently I found an intake leak from a hole in the manifold tube and replaced it on my Number 3 cylinder. Funny thing is that before the leak, my CHT's were very stable and all cylinders were almost always the same or within just 2 or 3 degrees.

Now when I climb out, my CHT's have about a 20 degree difference between the front cylinders and rear cylinders. In cruise flight, the CHT's are all within ~5 degrees if I keep the EGT at 1325. That seems kind of rich to me.

Any suggestions or is this normal and I was just very lucky with my intake leak?