I installed the CALAS HP oil pump and scavenger pump today. It is a very easy job. Everything fits very well and there are only a couple of things to watch out for.
On the scavenger pump, the studs need to be 1/4" longer for the added length of the gears.
On the feed pump the drive tangs on the cam need to be radiused to match the slots in the pump gear. The bolt pads on the pump body are 1/8" thicker and this makes the studs a little short. I found that the stock return pump studs work good to replace the original studs for the feed pump. The bolt that goes through the cam cover into the case is too short and is easy to strip the case threads with the new pump. I had to make a special longer stud for this location.
The inlet fitting on the feed pump is a stock type fitting with 7/16-20 threads into the pump body. The pump is also available with 1/8 NPT threads but that must be specified on order.