Each of the last two years, former SB Nation writer Jimmy Kempski has put together a ranking of teams' defensive front sevens by weight (2014, 2013). There does not appear to be a correlation between weight and performance against the run, but it's still a little interesting to gain a little more context about each team.
The San Francisco 49ers entered the 2013 season ranked No. 19 with an average weight of 268.4 pounds along their front seven. This season, they could enter the season with a similar weight, or at 267 pounds. That would leave them ranked No. 24 or No. 25. These weights are all estimations at best since the only truly official weights come during the NFL Combine.
Jimmy uses the Our Lads depth charts to figure out each team's front seven. The depth charts are not perfect, but they give us a starting point. The two differences from this year compared to last year is Michael Wilhoite listed at starting ILB over NaVorro Bowman, and Glenn Dorsey starting at nose tackle.
The 49ers will eventually get back Bowman, but for now Wilhoite is the front-runner to start. If Chris Borland ended up claiming the job, the weight would jump eight pounds, as he is currently listed at 248 pounds, to Wilhoite's 240 pounds. I'll continue predicting Michael Wilhoite as the starter, but this will be yet another training camp battle to watch.
Ian Williams could still claim back the nose tackle job, but he remains a question mark heading toward training camp. He is rehabbing a broken ankle that also included ligament damage. Williams hopes to be back in time for the starting of training camp, but when you hear "hope", that is not quite as confident as I think most would like. If Dorsey retains the starting nose tackle job, I'd be curious to see what kind of role Ian Williams gets.