I have assembled some, but I never have done it all, and certainly not the first one or two I had done. Where I lived when I did most of them, the machine shop was very good but a little out of the way. Found what I hoped was a good block, took crank and rods then pistons out and got it to the shop. I let them poke out the cam bearings, then they measured and checked basic block integrity. Told me what bore they could do, which gave me the pistons I needed, yada yada yada. So, you will need to cultivate a relationship with a good automotive machine shop. I shop out the block boring/honing, cam bearing align bore, mains, etc. And the head refurb. Assembly is kind of fun, still some very specific steps to take with piston rings install and orientation, each engine manufacturer has their own quirks. I did the crank and rods/pistons, oil sump, baffle plate, pan, timing gears, front coverr, install heads and assemble the valve train. valve covers, oil pump, distributor, accessories, mounts, tranny install and hookup. That was a typical first day (j/k). All of that took about a month with machine shop, head shop and parts vendor lead times.