So you have been off of deadlifts for a month? Might not really be an issue so long as you have been going after your squats with gusto. It will be interesting to see if you can get there. 40-ish lbs is a pretty hefty jump, but it isn't impossible by any means. Well, at least not at this stage of your training. Give it another few years and 40lbs in 2 years time might feel like winning the lottery