I have a 1978 carbed 308 GTS. It has been running great! No problems starting, it has plenty of oil. When I drive it, a mystery noise has started when I hit around 3500 RPM. I'm doubting it's a rod as I have checked out some youtube videos and the sound is different. It's almost like MAYBE a fan could be hitting something when the revs get that high? I'm afraid to go faster to see if it goes away or gets worse. And if the revs go higher, the pitch of the vibration goes higher as well. Anyone ever have this one?