Don’t do it. Just machine the heads and use the right springs. The guy that did the porting on the heads for my 340 told me I would be fine running single springs with my Lunati cam, I believed him because I didn’t want to spend more money machining the heads and installing the required positive seals. And he was a long time machinist and Mopar guy so I believed him.
Guess what? I destroyed a set of rockers, because that guy didn’t know crap about my cam or what it needed (despite the fact that I told him exactly what I was using). The singles he said would work didn’t have all the same spring pressure specs, and I destroyed a set of rockers before I figured it out.
You already have the right springs and hardware, just have the heads done to use the right stuff.
