I finished breaking in my 1978 K-10 over the weekend. After that, I hooked up the kickdown on the tranny, then it was off to the old dark, secluded highway for some fun. Well, it works very well, it kicked down when I stepped into it at 55 and got up to 85 in a few seconds(3 or 4 )... it had one drawback... the nose came up, enough to lose some steering ability. Had to let out of it, also figured that was enough for the engine for one night.