Hows this combo sound ?

The crate motor isn't a bad motor, but a couple of things....

1)the cam in it, is too mild for a mighty demon, and it's a little small for the 750(at least in a demon since it's wet flowwed)

A 650 speed demon would be a better choice on that motor.

2)it's 75-100 horse shy of an 11.99

Assuming the car will weigh 3400 with you in it, you will need 390 at the WHEELS, so 380 crank hp isn't going to cut it.

380 crankhp in a 3400 pound car should yield a high 12, in optimum conditions.
A friend of mine has a dart with a 340 that hasn't seen a 12 yet, with hp dyno'd around 380(or a bit better). His car does have full interior, ect, and his converter isn't matched to the application very well.