Smokes now, didn't smoke before

Well when I bought the car a month ago, it didn't smoke. In that time all I've done to the car (engine related at least) is:

new gas tank
new gas (with some Gumout carb cleaner)
new sender
new oil (with a little Marvel Mystery Oil)
new oil filter

Now the thing smokes like a chimney. It HAS to be the MMO or the Carb Cleaner - right? I'm NOT using any lead additive. Any chance that's doing it?

If not, I'm a moron and didn't notice the billowing, noxious smoke when I purchased it. Yes, I did check

-Aaron


Houston, TX - 67 Fastback in restoration. A-code, C-4, 9" Traction-Loc rear.

"If you wish to make an apple pie from scratch, you must first invent the universe" - Carl Sagan