Dear Aaron,
A paper by Clark et. al. which studied the affect of different analogs on DNA methyltransferase showed that while dG and 7-deaza-dG will inhibit methyltransferase to a similar extent, they did not review the scenario where dC is upstream from 7-deaza-dG. The findings show that dG and 7-deaza-dG have similar properties and therfore, dC followed by 7-deaza-dG may be tolerated by the DNA methyltransferase. The only sure answer can be found by experimental testing.
Best regards,
Elizabeth