LOL. For one thing, there is no such thing as a “good” timing chain.
They are used because they are cheap and you can put a dot on each gear and Chimpo the trained monkey can install it.
All chains and the chainwheels (sprockets) they run on wear out. And they wear out quickly.
The SBM has one of the longest, if not the widest center to center distance of any V8. It certainly is the widest of any small block.
You can run the tensioner on a roller timing chain. It will wear into the rubbing blocks but once it gets down to the rollers themselves it will stop wearing. The rubbing blocks are made of UHMW or a similar materiel. It work hardens as it wears.
I defy anyone to show me an SAE white paper or any other scientifically tested paper from a reliable source where the weight of the fuel pump eccentric caused an issue.
That eccentric is so close to the center of the shaft AND and turns HALF the speed of the crank that what little is out won’t be anywhere near outside of industry standard race engine balance tolerance.
Thats picking the pepper out of the fly ****, and it’s not new. This has been debated for decades and the end is it doesn’t matter.
I won’t put together an engine with a timing chain and not use a tensioner. As long as one was available.
In my world people would stop stepping over donuts to pick up dog **** and they would buy a Milodon gear drive and never look back.