Need help deciding on a 360

Or you could think of it backwards.
We know 400/450 makes a real nice streeter, especially when it also has 450 torque down low. And we know almost any old SBMer will take 7.5psi.
So, 7.5/15 = a 50% power boost
So; 450hp/1.5 =300hp in the engine.
So; if you want a fuel sipper build a really tame 360cuber. 300/360= .83 hp per cube, shoot that is easy.
Or; if you want to hear the cam, build a teener;300/318= .94hp/cube. Shoot that teener will still make a mountain of torque.
Or; you want a radical 273? Well now yer pushin the envelope, as to driveability, and certainly the mileage went out the window.

Hyup, if I get a do-over it's gonna be a mild 360T. I squeezed some pretty good mpgs out of a 223*cam. Ima thinking I could do better with a 210 to 218 and still have a mountain of torque. I just might need some better rods......
So I'm seeing an automatic and 2.76s = about 2200@65 on the hiway, and I'm seeing those 2.76s hit 60mph@5100 with a 2.45 low gear and 5% slip. I see 5900 with a 2.74 low. I'm seeing a lot of tire-spin and smoke, and Ima hearing this weird whistle I just cant put my finger on.......
Maybe a two stage system; a little un up front and a bigger one remote mounted......
What I don't see is those 35 pounds of parasites called mufflers.