I just got a set of Granatelli BBC fabricated valve covers with the billet rail. They will be going on a 460 , 13:1, 248/254 653/660 , est about 650 + hp. What are you guys doing for breathers? Do I need them? What kind/ style are you guys using. Do I need a pcv valve . The valve covers are chemically polished and I don't want to have to weld on them. What to do?

I run no pcv valve...using Moroso stamped steel valve covers, with Moroso breathers that look like K&N's,,,raised slightly above the valve covers to help prevent blowby, hard to do when ya have all that swinging around in the crankcase.

Better off with Pcv saves puking oil after 1/4 mile run mufflers dont like pan evacs. Can you give me specs on your cam it smells good to me Bob

I just did this today, in fact, on a new set of BBC fab billet aluminum valve covers...

Bored three 1.23" holes (I like them snug), two in one cover and one in the other. One hole in each cover is for K&N push in breathers. The other hole is for a push in oil cap.
Same motor, different covers (cast Darts), I did the same thing last year...no problems. See signature for pic...
I do not run a PCV (no issues, either) but you could easily omit one breather and install a PCV grommet instead...same size hole. ;)

I can't find the damn cam card...specs are similar to a xr286r??? billet core on a 107 lsa, 656/661 286/294 adv. 248/254 @ .050 something along those lines, leaves hard and pulls hard, I like it.

Pick up a pair of Offenhauser 6.000" long polished breathers and forget about everything else. They go on street/strip drag cars and street rods with no problems at all. Very easy to install. We have them on a 7.45 / 180 mph. dragster we run. Don't worry about PCV. Gary