It's nice to have a couple fresh builds to compare between. I have the stock build in my 69 and the above mentioned build in my 79. They run almost exactly the same. They like the same octane. I have stock exhaust so you hear every little noise(ping). The thing about headers: I had headers on my 79 and then switched to stock exhaust. My engine didn't ping until after I installed the stock exhaust. Ah, oh, maybe it was that I wasn't hearing it? The 79 runs cooler than the 69. I attribute this totally to the manual trans in the 79. It's going to hit the 70's today. The biggest challenge with having these two is driving both! OK I'm bragging(again), sorry.