261 motors ran hot normally, hotter than the 235 because the 261 not only had a bigger bore it also had a higher compression
I don't know about canadian pontic 261s, but chev truck 261s in the states ran LOWER not higher compression than a 235. years ago I didn't know any better & ran an 848 head on a 261 with a 235 head gasket without drilling the steam holes. that truck was a daily driver & I never overheated. I have an 848 head on my current 261 which I drilled using a 261 gasket straight in with no problems. however after seeing your cross section next time I'll drill them at an angle.
