Tap and die sets include a gauge that calculates threads per inch. Select the corresponding die that matches with the reading on the thread per inch gauge, and set the die in the handle that comes with the set.
The IROC-Z model of the Chevrolet Camaro first made its public appearance in 1985 as an add on option to the 1985 Camaro Z28 model. But its origin began long before that. IROC stands for International Race of Champions which is an automobile racing series similar to what NASCAR is.
The COPO Camaro's. Yenko Chevrolet and COPO 9561. Perhaps the best know of the racing dealers is Don Yenko, from Cannonsberg, Pennsylvania. Wanting more performance than the 396 Camaro would give, Yenko Sportscars created the Yenko Super Camaro by installing the 427 cid 425 hp engine.