[JLMounce]

I don't know much about the software on those things, but depending on the model number it may be undersized. The 2900 basic kit is rated up to 525hp while the 2910 kit is rated up to 620 hp.

It's my understanding that the original 1.0 atomic kits have no ability to tune beyond its handheld, while the newer 2.0 version likely uses the same tuning software provided on the Sniper.

In either case, if the 496 in question is a true 600hp, you've maxed out the 2900 kit and your very close with no room to go any further with the 2910 kit. I'd be looking at either swapping out the injectors, or going to a different fuel delivery option.

Of the TBI type systems, I would go with one of the FiTech units here. If you are not running timing control and have no plan to do so, I'd opt for the MeanStreet. It is 800 hp capable and designed specifically for engines like this at a slightly lower price point without the need to control timing. If you do want to run timing control I'd opt for the 1200PA.

For this engine I like the FiTech units specifically because of the price point on the MeanStreet, or with the 1200PA, it's off-idle tunability compared to the big Sniper Stealth units. The 1200PA uses 8 injectors to reach 1200hp capability, but in cruise and low throttle applications, it shuts down 4 of the injectors, which gives you much better manners on the street.