Disappointed in my 383 on the Dyno

So went to get some tuning done and my 383 only laid down 329 hp and 356tq to the wheels on a Dyno jet. It’s bored 40 over, 10.1 compression, with the edlebrock rpm top end kit (heads,can,full roller setup, intake manifold) with a 750 qfl carb. TTI headers mated to a 4 speed with 3.91 sure trac rear. Aside from adding some giggle gas, best bang for my buck way to achieve 400-450 to the wheels?