Most of us here have been there too,and we all try our best to help others "plan ahead" so they wont get stonewalled halfway through a project--or worse,have to take it apart again and start over..
I've learned a lot here over the years,and the members here are good teachers,and don't bust your nads if your not that well educated on vehicles..
When I first got my diesel pickup,I knew squat about diesels..
But with the help of some members here familiar with them,I was able to get mine running and keep it running..if not for them,I'd have ended up swapping a gas engine in the truck probably.
Its hard though--despite Chevy being one of the most "interchangeable" engines ,there are a LOT of minor differences that were made over the years,and only "some" parts will work right,even though they might bolt together OK...examples are the externally balanced flywheels on a 400 small block and the 454..they'll bolt up to just about any other chevy engine,but wont work right,it'll shake the engine off its mounts and possibly bust the crank..
One guy I know put some used rocker arms off a 400 small block on his 283 when one of the originals broke,and couldn't figure out why it now idled rough...turns out only the 400 has a different rocker arm ratio than all the other small blocks,and the valves with those rockers were opening more than the other 14 valves,so it wouldn't idle right..
He put three different carbs on it and it ran the same..then he told me how "it ran perfect till I messed with those rocker arms"..I happened to know they were different despite looking the same--I gave him some rockers I had off a 305 and it ran nice again..two local garages insisted his cam had flat lobes and he should "just junk that motor"..

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