Has anyone found that upgrading to a true double roller chain is worth it? Stock valve train, cam etc. Just want a simple bolt on replacement for my stretched link belt type.
Depends on miles you plan on driving and cost. If the engine will be rebuilt in a year or two, don't really drive much, or you can hear a roller chain over engine noises, a flat link chain is fine for ~$20 Daily driver, heavy duty use, or you don't like having to adjust your ignition timing every 15Kmiles, get a roller. And if you do get a roller, make sure to get one that has proper oval links, not those '8' shaped ones. FWIW, on my OT emissions tested vehicles from the 70s-80's I put a roller timing chain in those as it keeps the timing spot on for over 50Kmiles. A flat link will start to show loss of synchronization after 10Kmiles, regardless if the cam sprocket is metal or nylon coated.
I've got the engine out for a rebuild right now. Is their a noise difference between link belt and roller? I like my engines quiet and my exhaust loud!
If you're going through the trouble what you probably want is one with adjustable keyways, so you can measure and install the cam at a truly "straight up" or even an advanced position. Most people with a street rod will prefer this. Any chain will stretch somewhat and tend to retard the valve timing. Valve timing or cam phasing is not the same thing as ignition timing.
Loud exhaust note will mask any chain noise. Stay away from nylon cam gear. Heat on top of normal wear.......... Joe