You got several guys here that gave you great info.
I dont get much time to get on here.. however I am building a 407 SBC right now.
I build custom HD for a living , and the same questions get asked for these as well. Nothing more than a air pump plain and simple.
I see that when you start wanting a hp goal that the street side of the kit goeas to the way side. A 450 hp small block is a fun engine on the street. At the track there will always be guys that are faster and have more.
If the truck is really going to be running on the street then build it for that 80%+ use factor. NOS is always a fun way to get power for the track % ( as none of us would EVER hit the button on the street LOL)
I am running RHS 220 heads, a howards retro roller cam ( HRS 110275-10) that is a very close copy to the XR 294. I looked at the 304 as well. But did not want to kill the street side of my truck. comp level will be 10.6-10.8 once we see where everything stacks up. 850 street demon carb, and I am happy that I will no longer have to run the valves after a hard day or two of driving. Something to be said about less up keep.
We run hyr rollers in all of these HD engines with seat pressure in the 180-220 range and 450-550 on the nose with cams in the 660 lift area, some where we bump from the 1.6 rocker to a 1.7 . These lifters are stock and they handle it all day long, RPM ranges up to 6500 is the norm. And a air cooled engine. SO it can be done.
Running a tko 600( .64 over for the super slab stuff) with a 3.91 gear on 27 inch tires
for the street.
Over all it will not make huge numbers but will be a stout street machine that I can hope in a drive any where in the us I want to go.
Having had many race cars and trucks I can tell you that I dont miss them. Too much work, and I dont have the time to be messing with them all the time.
Things are changing that is for sure you can buy a CTS car that will run 190 mph off the show room floor and have a heated steering wheel as well .
The new gt stang is a 200 mph car. You can have it all , as long as the budget is big.
Having said all of that, I can say from my stand point I made a few changes in my build from where I started. all to have better street use vs a dyno sheet. Its just a piece of paper nothing more.
You make all this power but can you then put it to the ground and hook it?? A big hp engine in a auto will the right convertor, a rear end to handle the power, and a set up to hook it. Beat plenty of rigs at the track that had me by well over 100/100 if you cannot put the power down and get the sled to move you get beat. Smoke shows are great but you dont need 550 hp to turn tires into a mass of rubber on the ground.
Ask SUPER he runs on a regular basis as well does Marv. DO it right the first time as I am doing over this go round. I have about 14 grand now into the two engines total, as the first went went south. I hate do overs and they cost you a ton of money.