Main Sail Reefing system loads....

[NCountry]

I have a Gulfstar 44 that I'm going t put single line reefing on the main. Part of the system will involve cheek blocks on the boom. Anyone have any knowledge about how much of a load I can expect on these blocks when single or double reefed? Just trying to get some estimates so I can size the blocks properly.
Of course my first guess was to just buy the biggest ones I can get to fit.... but then I ran into that nasty budgetary consideration....

[ice]

roughly 1100 lbs