Maybe a Canadian member has specs for the hydraulic cam used on 261-equipped Canadian Pontiacs?
I am not recommending changing/keeping the "modified"-lift mechanical-lifter cam that was used on USA truck 261s (and many 235 Corvettes).
My original cam 1960 261 (bored 0.060, resulting in around 270 ci displacement) has plenty of "oomph" (using a GMC 302 2-barrel carburetor with adjustable main jets).