Looks like a late 70's very early 80's 258 block with a 4.0 head. The 3rd pulley was used when they had air pump style emissions. You can get rid of it, you only need 2 pulleys on the crank. (just have to shorten the bolts, make sure they don't rub the timing cover)You will need a 2 groove pulley on the water pump if you want to go power steering. The one you have (not pictured) is probably a double.
If you are going to go EFI, you will probably want to start looking for a 84-86 aluminium intake. The MPI intake that you have was designed for air only, not air fuel. Never heard of anyone doing the head swap keeping the MPI intake unless they kept the MPI. Obviously it works as you have/had a running engine. But Howell may say you can use it with EFI, not real familiar with any FI. I thought the Howell kits used the 84-86 intakes.I did the head swap, used the 85 intake and am staying carb'd. Here's what that looks like. Not complete, but getting there. You will need the 4.0 intake/exhaust gasket. (Again, check the pics in the link below)
You may want to get a later model exhaust manifold. The kind that has an accordian section at #1 and #6 cylinders. Just what was recommended to me and it came with the head I picked up. Some say it is less likely to crack. Might check yours for any cracks in the tubes. BTW, there is a torque sequence for the intake/exhaust manifolds. (again, in the pics in the link).
Adapting the 84-86 aluminium intake is easy. Here's how I did mine.
I kept the EGR set up, not at all necessary and most that do the swap just block the EGR or leave it in not hooked up. If you are looking to keep "stock", leave it.
I did get some studs from McMaster Carr to mount the intake/exhaust instead of using bolts. (pics at the end of the intake/exhaust link) It was easier to mount the intake/exhaust. Not necessary, but helpful. Check VACJ7's build thread. That's where I got the idea. There are a few places on the intake/exhaust that you may need larger washers for. If you search 4.0 head swaps, you will get a few different ideas and spots they are needed. Check Gojeepins posts. He did a nice job and what I tried to recreate.
With the EFI, you will be able to adapt a stock air cleaner as well. Will kinda hide the EFI.
With the rebuild. Hopefully the rebuilder figured out that it was a 4.0 head and used the proper parts. As for the "rods" you mentioned, I am assuming you were talking of the push rods. Some who have done the swap say the 4.2 rods fit fine, some said they needed the 4.0. If the builder measured, he should have put the correct ones in and the valves are to spec.
The one thing you don't know and will have to ask the builder and/or PO, were the coolant passages on the 4.0 head blocked off and a 4.0 head gasket used, NOT the 4.2 head gasket.
If you are going power steering you will have to mod one of the brackets, but again, not a big deal.
That oil tube looks a little ummm.... weak. Most who replace them use a 4.0 set and modify a bit. Remark where full and add are.
That's about all I have. Good luck with your project.