Yes, lifter bore spacing is the same on both engines. What engine are you going to be building. As Beater said, the camshafts will interchange, but most cam companies don't have cores for a 292 engine, and swapping a 250 core into a 292 can cause other issues as well, like rod to cam interference, 250 cams aren't notched for the rods like a 292 cam is. Also, since no one offers a hydraulic roller cam or lifter specific for these engines, there are many critical issues that need to be considered before someone just trys to make something adapt to the 6 cylinder engines. The lifter length is important, because it has to have the oil groove passage in the correct location to supply oil to the rockers or they will starve for oil. And usually using a reground cam makes the base circle too short to put the lifter in the correct location, so both cam and lifter design together are very important to making a hydraulic roller setup work correctly for these engines. If they have never made a roller lifter for the Chevy 6 before, chances are they will try to adapt a SBC lifter because it has the same GM diameter, but because of other criteria, it will not work in the 6 cylinder engines.
There has also been previous discussion on this subject here before, so you might be able to find additional info searching the archives that might help out.
