ST Racing Concepts Aluminum Caster Blocks for Traxxas Slash/Rustler/Stampede (Red)

Love these caster blocks. The bottom hole needs to be drilled out (very very carefully) to accept the titanium pins. Not sure why they're that way, but, they are. Still well worth it. They hold up under all abuse I can throw at them.

First, they don't work with Lunsford Titanium shafts, those pins have 2.54mm in diameter, 2.50mm is the hole. And those caster blocks don't fit into Proline arms, need a little cut.
Seems a little stronger than Traxxas ones.

bought these to resurrect my Rustler, found out that the stock Traxxas suspension pins won't fit in the bottom hole. Don't know what pin is needed...the thinner suspension pins fit right through, but are too thin for the arm itself. NOw I don't know what I'm going to do with them. It appears that they may need to be tapped, but nothing is mentioned under their description.

Can't quite figure out what I'm going to do with them, since I can't return them now (packaging is open).