My shop truck is a '72 Doge 1/2 ton with a 360/727 combo with a Holley 4412. Over 100k and all I've done is a valve grind in the 20+ years I've owned it. Tows my race cars and anything else and still has lots of grunt left. ONCE in a while I'll get a lifter that won't pump up right off the bat, but it will if I shut it down, refire it and then let it warm up a tad. I don't even put it in gear until the tic tap goes away.