The W5 is the small block equivalent to the Stage 6 for the BB.
I fixed piles of those things.
At the end of the stage 6, they had somewhat gotten it sorted out.
The Zeus casting heads had most of the really troublesome crap taken care of.
Then there was the version of those castings that got sent to Chapman.
Those were really nice heads...... but MP priced themselves right out of the market.
They were over 4K for a pair of bare castings that needed custom valves and rocker gear.
