There's no such thing as a "high volume" pump for a 235/261, at least until I get through making an adapter to use a small block V8 oil pump on a stovebolt six. That project is in progress right now. The Melling M45 pump is as good as it gets right now, and one of them on John's 261 was making 70-something PSI during the initial run-in. That should be enough volume to handle all the oil filtration that even I could dream up, IMHO!
While you're drilling and tapping, also thread the camshaft snout and use the same push tool that you use on the harmonic balancer to install the timing gear.
Jerry
