Edelbrock 1406 whistling

if it still runs like crud and is still whisteling ....then it sounds like things still need fixed.

hard saying without being hands on in person.

but a compression check would definitely not hurt anything.

do a compression test and a leak down test.

and hook up a vacuum gauge......normally if there is a "whistle" you have a vacuum leak.

but some of your symptoms sound almost like bad rings or a tipped or hung valve or something.