Mast Raising System--Gear & Tips

I studied the Mast Helper pictures and watched the homemade Texas video to figure out how best to make a mast raising rig. For the side control lines I used old braided nylon rope with old bronze snap shackles at the ends. The previous owner of my #5372 had attached an eyestrap underneath (not on top) the gunnel on each side and actually several inches forward of the maststep and not directly alongside (?). My poles are made from 1 1/4" pine closet rod 5 ft long with braided rope thru the crossed rod tops with bowline loops. Letting the mast down was a cinch at the lake parking lot last week. But at home on the trailer in the yard beside the garage, I had a problem raising it back up. When raising the mast, it wanted to go sideways severely, so I relowered it and tightened more the sidepull rope on the opposite side of lean. I was able to get the mast up but had to twist the mast base by hand to get it lined up with the boat maststep. I figured the problem was my boat was not on level ground...checked with a bubble level....I was correct. I think my side pull rope also stretches. So I was thinking I could rig each side pull with steel cable (instead of rope) with a thimble at each end nicropressed in an aluminum sleeve (Lowe's said they would press it for me). I could easily make each cable exactly the same length....but this material I would not be able to adjust like a rope sidepull with knots (?). I need to reposition the eyestraps backward to be directly beside the mast step for even tension during the entire raise or lower (constant triangle). I saw one person at the Lake Norman Regatta 48 on Nov 1 who had the mast helper system and had to twist the mast at the end of raising to make the mast base line up with the mast step. His trailer I guess was also on not quite level ground. Just wanted to start a discussion on mast raising gear and methods to get your ideas. Jim