If your discussing 60's blocks in terms of actual machined surfaces I can only think of one area;
The drilling for
oil feed from front cam brg tunnel to distributor spigot- 289 feed goes thru block only with tiny 1/4" plug in front face---302 uses groove in cam thrust plate.
It was not uncommon to find blocks with 302 cast# in valley that had been original equipment in 289 cars from new at time of crossover, have a motor from 67 Aust Ford Falcon in shop at moment that backs that up.