Youve got four big holes and four PVS holes, correct? On my 2012 Cougar, I started with four small plugs, but on the hole shot, RPMs got up to about 5,500 and with a load it would just sit and spin and break over after 10 seconds or so. I bought some solid plugs and have settled on three solid, one small. Breaks over at 4400 quickly with a light load, have not run it loaded with the solid plugs.Installing the plugs for some reason is hard on this prop the way it is drilled. I used a small flathead screwdriver, lightly tapping on one side of the plug flange to get it half seated. I really had to work at it but eventually got them in. A small socket or dowel is needed to finish it, but I would not have gotten them in without carefully using the screwdriver.