I think the part number was 90350404. The adapters were about $6 per unit, plus I bought some rubber washers that they said I needed. Hope I got the right parts
It was described as 1/4 BSPP male, 1/4 NPT female. Don't have the block in my hands yet, but I'll let you know how it works out.
I must say, HighspeedPC.com was the best online company I've ever dealt with. Very responsive, and shipped the block next day. I'll order from them, whenever possible.