I have built my share of engines in the past so, I hope I can help. First, the closer you keep it to stock the, easier and cheaper the build will go. If you change any one thing that change will affect other parts of the build. Sometimes the change is good and other times it is bad. The 454 has always had issues with air flow. I would recommend changing the cam out for one that has more duration. This keeps the valves open a bit longer allowing for more air flow. I would also highly recommend you have the valve ports opened up and have larger valves installed. Don't forget hardened valve seats for unleaded gas. An intake is a good idea just make sure you keep it a dual plane and make sure it will work with your cam selection. An intake is not always needed. Port match the intake with the heads and open up those ports. Same on the exhaust side. Now, with all the work above on the heads you maybe thinking about an aftermarket set of aluminum heads that already addresses these changes. And that is a great idea, lower weight, better flow, no added machine work, and their is a plethora of choices. Edelbrock heads are a great idea here. Compression ratio will be affected so, pay attention to the cc and head gasket thickness.
Exhaust on the 454 is always been too small on any factory set up rig. I am not saying you need dual 3" straight through pipes but, a dual 2 1/4 or 2 1/2" with a high quality flow through muffler will do wonders. I prefer Dynomax ultra flo mufflers myself but, the VT muffler maybe better for your application. No drone, very quiet until you want them to bark.
A stroker kit may also be a good idea depending on how far you want to get into the motor build. A 0.030 over bore and remove the 4.000 crank in favor of a 4.250 and you end up with a 496 or 8.1l.
My last recommendation should be the first. Fuel injection. This will make the motor more user friendly, and will give you a wee bit better fuel economy. There are a number of aftermarket injection systems out there.
LT.
