edelbrock

Anyone recall about when Edelbrock changed the engraving on the ends of their heads from “Performer 409” to “Performer RPM 409”? Did the early heads have machining issues, or was that just limited to the sheetmetal pushrod guides?

Hi, I recently purchased an early '58 348 passenger motor which needs some rebuilding (done by a qualified person) as I am not very knowledgeable with motors yet. However I am hoping to get some answers here on the forum regarding certain issues for my own personal knowledge. Thanks in advance...