In fact, there's already talk about the "Next Generation" of lifters coming out of Detroit. They will sport a lower profile to match up with an engine that sits lower in the chassis to present less upper engine mass to the car or truck's hood. And it's not just the engine's location, the engine itself is being made with less upper profile, mass and weight. The lower profile means the length of the lifter will be reduced, as will the pushrod length and upper parts of the block and heads. It's a challenging concept and entirely "do-able."
When installing mechanical roller lifters, soak them in oil for 30 minutes prior to installation. This will prevent dry start-up and excessive wear on needle bearings. At the Well's Racing shop, we use no oil restrictors on Chevy engines with mechanical roller lifters. We want full oil pressure to needle bearings in roller lifters.