First off, unless your car is morbidly obese, and you are dropping the hammer at 8k plus, no way on this green earth do you need an 18 split input. Jaunt don't need it.
You need the correct clutch. I have preached this for years and years. In fact, I just watched a video the other day about a ford guy with a high 11 second car test between a 5 speed and a PG. no matter what, the stick was quicker and faster.
As is typical, they used about the most junk clutch you can buy and it showed in the video. That clutch beat the car and the tire like they stole something. They were wasting another tenth and half to two tenths. Easily. Spend money on a clutch and your world will change.
Those heads won't know if it's on the street or the strip. Sit down with your engine builder and discuss what you want. I've posted the pictures on my heads on here with that same port. So I know what it is, and what it isn't.
That head, on 340 inches at 7000 RPM, done correctly will easily push 580-600 HP. Easily. On flat solid lifters. Maybe 630-640 with a GOOD solid roller.
If I was doing it, you be at damn near (and maybe at) 12:1 compression. I'd weld and fix your intake, and make and weld up a top to make it Dominator flange and hook you up with a custom Dominator and watch it ring the bell all day long. On pump gas. Like falling off a log.
That's what they are capable of. If (and it's a big IF) you sit down and make a plan, and then stick to it. And I forgot, you need quality headers.
You'd be surprised how easily it would drive on the street and turn heads at the track.