The weak link in the U joints is the bolts, as long as you have a solid U-joint. I think there is a U-bolt conversion available to prevent the bolted retainer failure. I watched a guy break his at the line at the track and that was the first thing he said - oops I forgot to do the bolt to U bolt conversion.
On my stroker I use the stock valve covers with the big grommet in the middle, on both sides of the engine. Big breathers and big hose dropping down by the headers.
