I installed a set of TFS heads on the 428CJ in my 59 over the winter, I am running ISKY iron adjustable rocker arms (no roller tip, but they do have a curved, hardened pad on the valve end). On my iron CJ heads, I had been running the Oregon Cams stands and support system, but milling the Oregon Cams lower plates would make them very thin where they are machined to clear the head bolts, (which is not needed with the TFS heads, due to the taller rocker pads on the heads). So I called POP, and he said that he did offer rocker stands that were machined lower, but only .100". I spent a fair bit of time trying different rocker stand heights, different length pushrods, and measuring lift at the valve and valve stem pattern, and for my application (mild solid flat tappet Oregon Cam, dumb bell lifters, the Isky rockers, etc), I wanted stands .230" shorter than standard, and 9.450" long "ball and cup" pushrods. I ended up buying the regular POP stands, and had Brent machine them down . 230". That does make the end support fairly thin at the head bolt relief, (which isn`t really needed with the TFS heads), but with the smallish cam and mild valve spring pressures, I don`t expect on issues in that area. I put 2500 miles on the car with the TFS heads this year, and currently have the engine apart for an unrelated problem, and the supports all lok fine. One thing that I noticed while doing all that mockup and measuring, was how much valve lift can be lost with bad rocker geometry. All my previous FEs had used factory iron heads, mostly CJ heads, and standard type 4 bolt rockers, (factory FE adjustables, Ersons, Iskys, plus HD Doves with the end supports attached to the head bolts), so I never really gave the geometry very much attention, but this was quite an eye opener. Pretty easy to "lose" .030-.040" of valve lift with bad geometry.
