[blykins]

You don't need the bushings, Bob, and it's a lot of expense to do it correctly. You can't just drill the hole and press a bushing in, it needs to be done with the block and a BHJ lifter fixture for it to be done right. Most hydraulic roller cams do not have the lift nor do they require the spring pressure to need anything near this kind of prevention, and you won't see any horsepower increases because of the bushings.

As for a solid lifter on a hydraulic roller, be aware of what's necessary here....you still need to run lash, and you will need to run a very tight cold lash, because hot lash needs to be in the .006-.010" range. Even then you still have lash, which coupled with higher valve spring pressures is what kills a solid roller lifter over time. There are many short travel hydraulic roller lifters out there from Comp or Morel, where you can adjust them and run high spring pressures and get more potential rpm out of your combo.