About 40 years ago, I did a frame-off rebuild of a 55 Chevy pickup, then lovingly stuffed a 500+ hp 427 in it. Took me 6 months to get it not done, but road worthy.
That afternoon I had a blast, but finished the day totaling the truck.
Sort of feel your pain. A buddy and I built a tweaked Pontiac Ram Air IV 400 and stuffed it in a 73 LeMans. After a bit of break-in, I rapidly scattered a chunk of crankshaft out of the side of the block somewhere north of 7K.
One of us, and to this day neither can say which, never torqued a main cap. Such is the life of the young, drunken 3 AM hotrodder.
Not as expensive as your foray into gearhead greatness, but it was a damn expensive mistake regardless ;)
My favorite truck! You killed it!