My only word of caution is that I've heard that jointed pelhams can muffle the signals somewhat and confuse the horse. This isn't from personal experience though, and there is of course exceptions for every rules in that there are some horses much better in jointed pelhams...
What kind of bit cheek piece wise is he normally in? If simply a snaffle, you may find that being able to apply a gentle amount of curb with the pelham even when straight bar, will be enough to to lift him and stop him pulling anyway...Obviously advocate the use of 'snaffle' rein primarily, but nothing wrong with using curb in moderation to help out...