Disappointing ET's with 408

I think the guys nailed it pretty good. The 600 carb. is holding you back allot. I personally haven't had much lock with e-brock carbs. I'd say use that Holley and dial it in. Remember jet it for best MPH. I think you'll pick up possibly 3/4 of a second with it. The headers are also a limiting factor but quite possible the stock pipes are the biggest hindrance. Try uncorking the headers and see what it runs. If you unhook it and it goes a second faster you know the exhaust is holding it back allot. The TTI headers showed a nice gain on that little 300 hp engine but don't expect it with your combo. If you noticed the 1-3/4 hookers showed a loss. That's because a little 300 hp engine can't keep up the velocity. If you do want to upgrade the exh. go with a set of 1-3/4 headers, 2-1/2 or 3" pipes to the muffs and don't use tailpipes. Just use turn downs. And get that timing coming in a little quicker. At least by 2500, preferably by 2300.

It looks to me by your parts list that when you get everything dialed in you should be knocking on 11's door.