Assuming they're going in a well-built ‘71 350 that's "moderate" in regards to horsepower (i.e. strong street engine, not high revving track engine), would you choose NOS GM lifters or new Melling lifters?
Melling is fine either way, unless your lift is past .525-.530 unless your running a 68-69 and using the oil thru head .
If you can get Delphi lifters buy them. AKA GM lifters.. if not go roller.. Delphi flat tapes are the only ones with the Harden seats.
I NEVER install ANY lifters without taking them apart & thoroughly cleaning them. You would be surprised at how much debris is actually in them. For the 1-2hrs. it will take is less than having to pull the engine apart again because of debris causing issues + the additional cost of gaskets/supplies, etc.. Just MHO Tom T.
You're not doing that with rollers. You can maybe plunge them cleaner, in spirits, then blow them out.
