Do it with Garhauer equipment
Practical sailor rated their equipment the best. Cannot beat the price/service/quality. I put on ball bearing cars with all the purchase/power blocks from Garhauer for about the cost of non-ball bearing harken cars with out the additional cost of blocks. When the cars are easy to adjust you will adjust them and make life easier & faster out on the water. And might I add, fast is fun. I also added their hard vang, and paid a nominal cost for them to fabricate the piece that would fit the underside of my boom. A pleasure to deal with them.