Hello, and welcome! But I need to ask some questions as I'm struggling a little bit getting my head around your post.
First, is your carb a 2bbl or 4bbl? The 351W came both ways that year, and the 2bbl version had a computer and the 4bbl didn't. So we need to know what we are dealing with.
Second, was it running correctly just before stopping as if someone turned off the key? Any backfires or poor running? And especially, had the oil pressure been changing?
I ask the above because the crankshaft turns the timing chain, which turns the camshaft, which is geared to the distributor, which has a shaft down to the oil pump. I bought a 351W on which the oil pump seized, which stopped the distributor. But the engine was still spinning so it broke the teeth off of one side of the distributor. I wasn't there when it happened, so I don't know if there was a huge backfire, but I can see that could happen as things come to a screeching halt.
The fact that your dizzy has teeth broken off says the dizzy stopped while the rest of the engine kept turning. That can happen with either the oil pump or the distributor itself seizing. In either case you have the teeth that must be found. And the culprit must be found.
What warranty on the new engine do you have? Hopefully you have one as it is possible damage has been done due to loss of oil pressure.
(And, by the way, it would help us help you if you could use a little bit of punctuation in your posts. We can only truly help if we understand, and it wasn't easy reading your post.)
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker in front & 10.25 Spicer/Trutrac in back, & EEC-V MAF/SEFI