i purchased a small block 400 engine for my project car. the previous owner was happy to get rid of it. said he could not keep valve guides in the heads for more than a thousand miles. being the small block fanatic that i am i just thought he was lost. after having the heads worked, replacing the cam with a comp.cams 292/501 hydrulic. harland sharp rockers and 7.8 inch pushrods the engine screems. i now have about 800 miles on the engine and it started smoking. after checking it out turns out the intake valve guides are wore out. several of them are oval spaded. i called the previous owner and he told me had already replaced them twice in the small amount of time he had this engine. anyone else run into this problem or have any experiece with these heads. the only number on the heade are 4767 on one and 4775 on the other. also i was told by competion cams to use these lenth pushrods but i have noticed that the bottom of all my rockerarm have been touching the rocker stud nuts. this tells me that i need loger pushrods. could this be my problem? anyone help please becouse i do love this engine.  

I've got a set of those here in the shop and they use ultra short valves and springs and the pushrods should not be the same as stock length (7.797").  Most premature guide wear is due to valvetrain geometry problems and I'm pretty sure that is the case here.  Take a close look at the wear pattern across the tip of your valves.  Regardless of whether the rocker tip is closer to the inner or outer edge of the valve tip, the pattern should be no bigger than .080" or you are having some major issues.  Use a Sharpie to mark the tip of your valves on the number one cylinder and drop in a couple of solid lifters.  Buy a pushrod length checking tool from Comp Cams or Jesel and set the length to stock to begin with.  Change the length longer or shorter by .050" at a time to get the smallest wear pattern you can on the tip of your valves and that is the length you want to get your pushrods.  Keep in mind that on a Twisted Wedge head the intake and exhaust may use different lengths.  

Just another issue with the Twisted wedge heads.  I have a pair and found that to get the geometries right and avoid valve guide wear there is a special rocker built by Comp for the Intake on these heads.  It's Comp PN 1309-8(1.6RR).  This is an 8 pc set for the Intake side only.  There is also a 1.5RR PN as well.  

I have a pair of the original SBC twisted wedge heads from TFS which have been discontinued for several years now.  Yep, that's the problem with these heads.  I had a a little trouble getting the valve train geometries right on these.  What I found with an adjustable pushrod, was my rocker arms would hit the rocker stud before the pushrod was short enough.  The TFS guys suggested Crane Cams gold rockers.  They do allow for a shorter rod.  I found that a 7.700" pushrod made for good geometries.  Any shorter and the rocker would hit the stud.  These actually are pretty good heads and make good power and torque.  I don't have very many miles on this engine.  Will provide an update after a few thousand miles.