Bronze lifter bores....
Hello, Bronze lifter bores are always a good idea in an "all-out" racing engine. The benefits include: truing the lifter bores to proper alignment and angle, reduced friction, the option of larger O.D. lifters and repairability of the lifter bore in the event of lifter failure. This can be performed by most reputable machine shops but it can be expensive. This is a smart procedure if you want to protect the investment of the cylinder block/engine but it is not absolutely necessary. Most racing engine companys do this now to protect the buyers investment anyway, because of increased horsepower and limitations on valvetrain it is more cost effective to spend the added time to install the bushings at the time the engine is assembled from new.