How was the 400 built? It sounds like you added headers, intake and performer carb to a smog era engine. Even a mildly built 440 should produce over 400hp (decent cam and compression ratio plus what you have listed above). I had a 440 in a 4600lb Monaco that would run 14's, a reg cab truck doesn't weigh all that much more. Hell, my 03 quad cab is only 5300lbs.

 

I had a 78 smog era 440 with all the bolt-on goodies, but even with the parts I put on it, it really didn't help with the factory cam. It may of had 260hp TOPS, but it felt like 350TQ for sure.

I started the truck yesterday and again today, I still need to mount the wiring harness, hook up the 02 sensors, and a few other small things, I mainly wanted to start it before I routed the harness just to make sure it works.

 

http://www.youtube.com/watch?v=A6pse-jNIMU

 

that 440 is badass !

 

He put an LS1 in it because the 440 was a piece of ****

 

Correct, the truck now has a 346cu.in. LS1. It origanally had a 318 ran a 19.3...slow, after 220,xxx miles swapped in a 440 with full bolt-ons, ran a 15.7 @ 84...much better, but most chevy 5.3 trucks run that with bolt-ons.

Truck sat for most of the time due to 7-9mpgs being easy on it. I bought a camaro, ran 13.5 stock with the ls1, every time I puty a part on the car it went faster, 11.5 with mild heads cam and stall. Now the camaro runs a 10.6 with a ls2 and a bigger cam 3600 stall and will still get 22 on the highway, something the 440 could never do, so out with it and in with the ls1.

 

http://www.youtube.com/watch?v=FrykiHuSKYw