VA-187
I just installed a VA-187 yesterday. It is pre-punch and it is fairly soft. The flange deformed when I riveted it in place.
I'm going from a baffle mounted oil cooler to a firewall mounted cooler, so this is a retro-fit. I was not able to use 2 of the pre-punched holes and had to add couple of holes.
The pre-punched holes are #40 but I enlarged them to use -4 rivets. I was able to get a squeezer on 1 rivet and it came out fine. I had to use a pulled rivet (LP4-4) in one spot and it also worked out well. I had the most deformation on the rivets that I set with gun.
In retrospect, I think I would have been better off using pulled rivets on all the holes.