Not to say it isn't a carb tune issue.
Are you carb savvy ?
You might wanna make sure the carb is in the idle circuit..at idle.. and then in drive/brake on have someone neck down the idle mix screws till it coughs and back to where its smooth...and set them both/all 4 the same. Ex. 1/2 to 3/4 of a turn out.
From there you can do a rough power valve rating check with a vac guage and choose one that about 2-3" less than idle vac while in gear...or choose one half the vac if automatic trans. Then you can lean the primary jets till it surges a hair at cruise 50mph or better..and back up 2 jet sizes..that's your primary cruise dialed in....then wot testing with the secondary...usually are close/on but might need a jet bigger....if you run into pinging...again...play with total timing by taking some out, 2 degrees at a time. Try and leave 2 degrees of cushion between you and the pinging, if so.
