You can use a low pressure mechanical fuel pump, under 2 PSI. Higher PSI will cause fuel overflow.

The float valves on the Mikunis should be number 2.3 (PSI)

Don't be surprised if you have to raise the jet needles one or two notches richer. You might need to change your main jets from 175 to 185 or higher.

Also don't be surprised if the fuel in the float bowls expands after you shut the engine off, and drips out the ends of the little rubber hoses. I never received any answer about what to do about that - charcoal canister, maybe?
Fire extinguisher - certainly...

It's easier to fit the K&N filters for the first time if the rubber collars are warm. Also, the rubber couplers for the carb/manifold connection don't quite have the right hole spacing, so you will have to elongate them.

Leave a gap between the throttle linkage and the stop on the manifold.

The linkage design doesn't allow much leeway to adjust the idle for each carb individually.

Don't even think of trying to start and run the car without the chokes if the weather is cool; you can make your own choke cables by modifying a bicycle brake or shifter cable so that the ferrule on the end is the right shape, the other end of the cables can be interfaced to the existing choke lever with a couple of cable clamps and a small piece of metal of the appropriate thickness
with some holes drilled in it; I used a brass Canadian dollar coin; works great!

Oh, and the jet needles can't be lifted out unless you adjust the throttles completely closed first; do yourself a favor and order some spare circlips for the jet needles when you order whatever parts you need; the needles are also easily bent.

Please tell us how they work for you; there is very, very little practical
information out there about the Volvo B18/20 installation.

Bill