I agree with others here that, depending on your experience with hotter cams on the street, 260*+ might be a bit of a burden in traffic. Now some guys run that duration and bigger, but not everyone would like what that cam will do to the idle, off idle transitions and maybe even cruise. Certainly a matter of personal taste and comfort.

Personally, in my 440 based 500", 250* was about my limit of comfort. I have ran 10 or 12 different cams from 245* to 260*.

And don't forget that the EFI will not like the lope at lower engine speeds. You will need to lock it out and manually set it until the engine smooths out and the O2 can give reliable readings.

And one last thing, with that much power available, it will take some time figuring out the suspension so that you can transfer much of it to the ground. And on the street, it will take a lot of work and experimentation to get 600HP or so to the ground. It can, of course, be done. But it won't be easy. Heck, 600+HP can be a challenge to hook consistently at the track for a street car.

It would be my suggestion that you pull back some on the cam. If you end up putting too small a cam in, you can always stab in a bigger one at some point. But the car will be more flexible and enjoyable with a cam too small than it would be with a cam too large.

In this kind of combo, a guy's first time rarely gets everything right right off. You just hope to get as close as possible without making any big mistakes and dial it in from there.