u/Journeyman070

Hi all, I'm filling CMU block cores (Approx. 3x5 inches and 8 inch depth) in a 1960s era house with high compressive strength grout. I have 4-ply 2x4 post resting on the blocks that supports a large span 3-ply lvl beam above. I have to fill the cores for 6 blocks stacked vertically (4 ft height). What type of grout should I use (psi strength, brand, use) and how do I fill the cores without causing issues? Expert advice is greatly appreciated!