'71 Demon Ebay turbo kit

Get a blow through carb and run < 6 psi. Send it!

That's engine #1. When you detonate that one or as a revision before it detonates get yourself some closed chamber heads (cast production or Speedmaster cheapies), Eagle SIR rods, some forged flat top pistons. Try to find a cheap single plane like a TM5 Edelbrock and run a water methanol kit. All these options are the lower cost options and keep you from spending stupid big money on the "proper" parts but are good enough to do the job and have satisfactory reliability and performance.

Bottom line? Your current engine isn't right for boost. The reason for my recommendations is it allows you to wade into the waters while learning. You can go big if you have a big budget AND knowledge. With knowledge you can perform just under those big builds without having to spend as much.

You want closed chambered heads and flat tops for the quench which staves off detonation. You could probably buy a set of Speedmasters for the cost of building a set of closed chambered Late LA heads. A cast crank isn't the best option but it would be good enough for a mild turbo build. The stock rods have zero place in a forced induction build. You will want a single plane. Throw the whole single/dual plane debate out with forced induction. Single plane is always the answer but with all that forced air in 360 inches and a cast crank you will do good with just a BASIC single plane (lower cost too). TM5's are almost free nowadays.

Fuel and spark are the most integral parts of a FI build. Timing retard, rich/lean conditions, fuel supply .... This paragraph may represent the biggest investment and definately the area that you need to get right whichever (carb or EFI) fuel system you go with. If you cheap out anywhere don't let it be on your ignition timing. I would recommend a cheap FiTech FI ready EFI for timing control if you use a basic distributor (locked out of course). If you use a blow-through carb you will want to step up to an MSD-6 Programmable along with O2 and MAP sensors. You can tie all that into your water-methanol signal to control when it sprays. Costs will be about the same. You will want to run an EFI pump or surge tank with either and just use the appropriate regulator.

This is a distributor I was going to look more into on my revamping of my Procharged 408" blowthrough engine.
Progression Ignition Might be a better route than MSD's Programmable.