Machinist will not build engine unless roller cam is used!
We highly recommend hyd rollers for all street performance engines. Flat tappet failures have been very common over the last 10 years due to a combination of changes to oil as well as the loss of Johnson lifters. Once Johnson went away the lifter market was taken over by low quality offshore parts and the whole thing turned into a mess. There are some bad hyd lifters out there as well so buyer beware. We use Gaterman lifters whenever possible.