I understand the concern for the solid roller lifters as they can be a problem on a street car that is idled around a lot and has several miles put on it. The other problem with the 427's that do not have the
oil galley through the lifter bores is they do not get as much
oil bleed of or leaked on them and the new lifters have a pressure feed sprayer to help
oil the roller bearing but with no oil galley this does not work.
We just finished a 482FE in an original 427 side oiler block going in a 68 Shelby GT-500. He drives the car alot and we went with a solid flat-tappetr because he did not have the oil galleys for the hydraulic roller lifters. This engine had a 2x4 set up and idled nicely and made 600ft/lbs torque and 660HP so you still can make good power with a solid flat-tappet. We had a 252/262 @ .050 camshaft with about .620 lift. Everyone was real pleased with the results. We always run the camshaft in with the outer springs and install the inner after the camshaft is broken in. Good luck with your project. Thanks Keith