chockablock vs cram full

chockablock and cram full both are adjectives.

Word	Noun	Adjective	Verb	Adverb
chockablock	No	Yes	No	No
cram full	No	Yes	No	No

As adjectives, chockablock and cram full are synonyms defined as:

Other synonyms of chockablock include chock-full, chockful, choke-full, chuck-full.

chockablock (adjective)	cram full (adjective)
packed full to capacity	packed full to capacity