Yes, I'm using stock rockers, the rollers would not work because of the 5/16" studs... however, the springs/valves the machine shop used appear to sit slightly higher than stock ones. I had posted that series of problems here on this message board when my pushrods were not long enough when building the engine. I had to order a pushrod length checker to figure out what length to order, and they were slightly longer than stock to make the rockers more of a 90 degree from the valve over to the lifter top (hope that makes sense). Anyway, that must be the problem. I was playing around with it last night and I think my only option is to find thicker gaskets or double them. From what I'm hearing I guess that isn't such an unusual thing although I've never heard of it before this. Of course, I could get different valve covers but I don't really want to do that. If anyone can find a part number or place to buy thicker valve cover gaskets, that would REALLY be cool. I spent some time yesterday looking for some but never got close. I'll look at Felpro, maybe even call them. Thanks to all!

 

If I were in your shoes, I would try to find two sets of gaskets with a steel core, these would probably do the job for you and they would be less likely to "squease out" when you tighten the bolts....

http://store.summitracing.com/egnsea...=KeywordSearch

 

That is exactly what I'm doing. Yesterday I had the local Checker Auto round up 2 sets of stock gaskets to RTV together but called Summit this morning and they told me stock cork gaskets are about .172" and the thicker ones they sell are the steel core ones, which are .313". Either the thicker gaskets or the double-stock set should raise them up enough. Thanks for all the great suggestions/help!

 

Well, I did a couple of things simultaneously, just to get past this problem. First, I had a couple of sets of normal cork valve cover gaskets rounded up, which took a day. I also had them round up another set of 16 stock 5/16" rocker nuts, in case I wanted to use the double-nut method. I also called Summit and ordered the thicker gasket, with the steel core. This would just about cover any angle of this problem. So, last night I went into the garage again....
I took some of the red, high temp RTV and stuck 2 of the stock cork gaskets together, for both sides. I let these cure up for a couple of hours (I actually did this earlier in the day knowing I wanted them to dry thoroughly). I cleaned up my valve covers, because they were certainly less than the cleaned up look that I had spent so much time on, with having to take them off/on about 6 times. Anyway, the double gasket appeared to give me plenty of height over the rockers and locking nuts. I torqued them down and started the engine, and voila! No knocking whatsoever and now I'm moving onto the next challenge this new engine and transmission throw at me. I'll take the stock 5/16" nuts back, they weren't that expensive anyway. I'll still keep the thicker, steel lined gasket coming, I may have to take them off sometime and I'll see if they work too.
Thanks for all the suggestions Mustangers!