Will my fiance criminal record from way back affect my K1 visa application?

It should not affect the K-1/K-2 visa process.

As a general rule, the criminal history of a US citizen has no bearing on his/her eligibility to file a fiance or other petition for his/her family member However, in certain limited instances, the criminal record of a US citizen may be of tremendous concern with respect to the US citizen's ability to successfully bring a family member into the US. Therefore, you must insist that your US citizen fiance agree to provide unfettered access to his criminal past. If he was ever convicted of acts constituting domestic violence or violation of orders of protection, then, a petition by him may not be approved by CIS under Adam Walsh Act, [2004I. Next, notwithstanding my earlier comment that the US citizen's criminal history has no bearing in the immigration context, please note that as part of the 1996 overhaul of US immigration law, where a US citizen was convicted of or suspected of drug trafficking or money laundering, the alien fiance or family member of such US citizen may experience difficulty in obtaining admission into United States. I must admit I do not have sufficient information to conclude one way or the other about the odds of obtaining a fiance visa, and as such, I suggest that you and your fiance should contact an experienced immigration attorney before you file any paperwork with CIS.

It should not be an issue. USCIS would be more concerned with your criminal history, if any, that that of your U.S. citizen fiance.

In this case, his conviction for the possession/manufacturing of controlled substances will not affect his eligibility to petition for you as his fiancee. However, the fiance petition must be filed within 2 years from the date of your last meeting in person. Thus, you only have a few months left to gather the supporting documentation for your case and to file the I-129F petition with USCIS.