Re: Harmonic balancer.
I dont disagree with Loeryder in some respects, as I do believe you get what you pay for and quality dosen't come cheap. However for a stock truck that only revs to 4500, you dont need an SFI Approved balancer (dampener). There are good products out there that are SFI approved, but that approval is not based on how well it absorbs 'harmonics' but on its safety rating related to rpm and some sfi racing dampeners wont be tuned to absorb the harmonics in the rpm range that a stock dampener would. From a slightly different angle, as I remember when the tci rattler dampener came out, the way it absorbed the harmonics causes it to rattle and this caused false knock on some vehicles. No personal experience on that, I just remember it written about in some magazines at the time and am mentioning it just to to say that there are horses for courses, just like other parts you select for your build. These motors aren't the smoothest, we all know that and GM wouldn't spend $100, when $10 will do, but for me a stock type replacement will work fine on most trucks. However, I'm sure they can be improved upon. Maybe a Streetdamper non sfi (cheaper 'street' version of a Fluidamper) would be a good choice as an upgrade from a stock type elastomer ring type. Just make sure whatever you pick is neutral balanced and correctly indexed to your pointer.
As for your 8" damper, I suspect as long as it fits, allows the crank drive pulleys to be in correct alignment and is neutral balanced, it wont be detrimental. Larger diameter dampeners as a rule of thumb were fitted to higher HP/rpm versions of the sbc for example. The later Vortec 4.3 dampeners are a tad bigger and heavier than ours but I think interfere with the timing tab on our motors. I will stand corrected on that though. Maybe that motor you have revs higher than the stock 4500 or there about? I think 'Hood' sells a dampener, or used to.
