I`ve used those for years , Ed Hamburger 's For 340`s/360`s Only used to sell them . A rod coupling will also work. Well worth the effort to install . Chryco
No, They just keep end play from effecting timing. I bought collars from a local brg supply. Same thing and only a couple $$$ each,
Rick
Logged
69 Swinger,3.54 Dana, 400/499, Stealth heads, Crower 262/266d, .686/.696L roller,11 to 1, 950 Bigs, E85 carb. Best so far, 10.82 @ 124mph through the mufflers.