Here's some stuff from one of my really old posts:

I used Trentec cars with Harken cleats mounted between the track and the mast base for 20 years. You can add additional lines to set up a barber haul system to set the cars where you want them. It's a bullet proof system.
[...]
The Trentec cars pull to the center with a bungee that passes in front of the mast through a pad eye.

The barber haul lines (red and green) go around a cheek block pop riveted to the corner casting, through the pad eye, through the lance cleat for adjustment and are tied to the shrouds.

The jib sheet is tied off with a figure eight knot in the Trentec car. It goes through the block on the jib, through a block that’s attached to the car with a shackle, through the Harken cleat and to the crew.



Don't put those swivel cam cleats with cars in the old style tracks. You'll eventually rip them out by the roots.