I believe half the panels are the same in 66 and 67. If you have a full panel that's cut big or the full box there is a code under the card on the right hand side (under the dotted line) that reads 1-190-38-01-6 (or something quite similar) which means it's actually a 67. There is no code on the 66's. I have a big blog post on Bazooka Baseball coming up tomorrow, I'll post the link here once it pops.
There's a good article here too:
http://www.sportscollectorsdaily.com...ooka-baseball/