Whats the deal with everyone scared to rip one up. A close friend of mine runs a 555 bbc with eagle crank and GRP rods, and spins it to 9000 rpm every pass. Another has a 598 bbf with Grp rods and spins it to 9000 rpm every pass. I run a 434 sbc with Lunati crank and GRP rods and spin it up to 9200 rpm every pass, sometimes up to 9600 rpm. I had a 532 bbc 4.625 bore x 4 stroke and turned it up to 9000 rpm every pass, it had a stock gm steel crank, and Bill Miller alum rods. The trick is in the valve train, you cant shimp there, T&D Shaft Rockers (or Jesel) are a must, well designed camshaft, good springs, strong push rods. We check valve train before each race and stay on to of springs. They are not low maintenance, but they winn alot of races. These are not drag racing engines, we mud race too. I can see where this may cause problems if you were running 1/4 mile maybe, but a run for us is under 3 seconds. So to the oroginal poster of this thread, it can be done and is done quiet often around here. The 555 bbc had been running for 3 seasons without a freshen up and upon teardown the bearings looked brand new. It will go back together with new bearings, same rods and crank with new rod bolts. It will get new pistons because we are raising the compression.
You must let your camshaft co know what you intend to turn so that they build the cam accordingly. We use either LSM, Harold Brookshire, or Bullet.