1966 Mustang Hardtop 289 4 Speed
When I worked full-time in the bodyshop, I would often run across metric bolts that were half size, as in 6.5mm or 9.5mm for example.
I have that cam in my 331. It comes on strong around 5K and wants to rev to the moon! I have the XE266HR in my 302 powered coupe and it has more low end torque. Custom cams are nice but I'm sure there are many off the shelf cams that will work great.I have the TW 170 heads on my 331 with a XE274HR cam and it's very peppy! I think you'll love the motor your building.
I forgot about those scalers...thanks! I just worked on it a bit using a steel brush cup in an angle grinder. That made quick work of the rust! I'll be seeing iron oxide in the Kleenex for the next couple of days. I'll use a needle scaler to get into those hard to reach areas on the block.