The answer to the original post is that yes indeed, there is a port and starboard spreader bracket. When installed correctly, the spreaders tip upwards slightly. If you think about it a bit it makes perfect sense. The spreaders ideally should only be under compression, and if you imagine standing on the stern of your boat and look at the spreaders and shrouds, they will only be under compression when tipped upwards. Unfortunately, I don't have a measurement.
If you do a pile of research you'll find out that the only correct way to fix the J/30 speader problem is to put in a through bar. I hope to do this as soon as I find someone to make me one, and check on some dimensions.
You'll always have the following problems otherwise.
1) Forward rivets will keep pulling out.
2) Front rear welds on the spreader bracket spreader mounts will keep cracking.
3) Bracket plate attached to the mast will bend and ultimately crack.
If you weld a strap around the front of the mast to hold the two stainless spreader brackets together, you actually increase the loads on the spreader brackets because they are further restricted from allowing the mast to naturally move backwards and forwards as conditions vary. The rivets may not pull out, but the loads on a part that should be minimally loaded become high.
While buying brand new Kenyon /Rig Rite brackets is the easiest way to make your mast good as new, the brackets are quite expensive, and they leave you with a mast with the original problem. Seems like you can put a through bar in for about the same cost.
