Building a 383 Gen 1 SBC 2-piece seal engine.Rotating assy. is 4340 steel crank,h-beam rods,forged flat top pistons,clevite bearings. As for the harmonic balancer,what diameter should I use and also give me the pros and cons of elastomer versus fluid types? I'm going to run the GM serpentine setup,don't know if that's an issue of diameter choice. Let me know what will be best for my setup,willing to spend the money for what's best for my application. Thanks

 

ATI Super Damper is basically the best on the market in my (and many others, including most notable engine builders) opinion. They're the only balancer approved for use by nascar, if it means anything to you. I'm not 100% sure for your 383, but i think you need the 7" version...they have a chart on their website that you can use for picking out the one you need, or just give them a call. They are very helpful people.

As a side note, they are rebuildable, and tunable for engine stroke and rpm. You just take them apart and replace the elastomer bands in them.

 

ATI's 7.074" Super Damper if you can afford it. Otherwise, even some of the better crate engine builders use more affordable products sold by Summit Racing under the house brand Pro Street label. Just look for the small tag on the damper.

 

This is an old post, but in doing my research today I discovered post by high performance engine builder (beautiful, show car level engines also) -apparently fluid filled dampers tended to kill bearing in high rev engines. The Super Damper's looked almost new with each tear-down.

I like the TCI rattler, but you can hear it on some engines. That's probably not good on our L98's with knock sensor. Nitro-Nicky