Comp Cams Small Block Roller Rockers...

I had a set on a 360 but they were Mopar perf. valve covers and had no problems but the adjuster does stick up quite a bit when the valve is open so I guess the only way to find out is 1. hopefully someone here will post saying yay or nay, or 2. try to measure the height of the adjuster when at full lift and measure the depth of the valve cover and give your self a little extra space for clearance.

As far as the hold downs. I'd say if the roller is very radical (which it probably isn't since you only need 320 lb. springs) get them. If it's a mild roller don't worry about them. My springs are 120 lb. seat and 330 open with stock hold downs and I have 1500 miles on it (many of which were hard miles) and have had no problems. If I'm not mistaken the Comp rockers have stainless hold downs and grade 8 bolts so they are better than stock. If you want absolute peace of mind and have the money, go for it. JMHO