Current setup is 440
stock stroke .30 overbore
stock steel crank
SRP pistons on stock LY rods
MP cam. .474 lift, duration 280@ .050"
stock 446 heads with 2.14/1.81 manley stainless valves. bowls bleneded but no other porting.
Performer RPM w/speed demon 750 carb.
builder told me it's 10:1 I ran it around for many years on 93 octane fuel.

the only performance data point I have is that it ran a 13.1 @112mph (lousy 60 foot, no traction) in my 68 charger with a 3.55 gear and 1 7/8" headers.

Currently has 3.91 gear and HP exhaust manifolds

I thik it ran pretty good for what it is which is a sub 400hp engine in a heavy car. I'd like to install a set of 440 source heads and new cam with headers. At this point with the larger volume heads, I'd probably spring for a set of 2" primary headers instead of putting the 1 7/8" back on.

I'd like a 500hp streetable engine and I do plan on installing an EZ efi 2.0 which I already have. I wouldn't do that until after I ran it around for a while on new heads/cam/headers.

questions:
1) what would be a good cam for this setup keeping in mind I want to convert it to EFI? I'm not sure if the newer self tuning efi's need strong vacuum signal at idle.
2) Is the juice worth the squeeze to go with a hydraulic roller?
3) considering this is a street build, is getting the cnc ported source heads necessary?
4) the EZ efi 2.0 that I bought 7 years ago is still new in the box. I see they still make it. does that mean this is ok to use or is there some other throttle body self learning system I should be considering?

Car hasn't run in 7 years... sitting in the garage collecting dust and I'm going to get it back on the road this winter.
Forgive me if I'm asking dumb questions. I used to live on Moparts but haven't been on in so long and I haven't kept up with anything.