Please note that this kit is with offset-screw saddles for American Standard Strats up to and including 2007.
This kit includes all the parts shown in the image above. It gives you everything you need to completely upgrade the Fender tremolo, retaining only the stock top plate and studs.
Block:
All Callaham blocks are made of 1018 cold-rolled steel like the vintage originals, which contributes to the sustain and harmonic content that has made these guitars legendary. Replacing a block made of inferior materials (zinc, leaded steel, sintered steel) with one of Callaham's blocks will make a real improvement to your tone.
Enhanced Vintage Design:
The block is Callaham's Enhanced Vintage design, which utilizes a Delrin bushing in the arm hole, for the arm to bear against. With traditional threaded block designs, when you use the arm you create forces that are concentrated right on the threaded portion of the arm - its weakest point. This is where arms typically break. Callaham's solution is to leave this bearing-portion of the arm unthreaded, and to insert a Delrin bushing into the block for it to bear against. (Delrin is similar to nylon). This virtually eliminates broken arms.
Virtual Pop-In Arm:
While Callaham's arm is unthreaded where it bears against the Delrin bushing, it does have a few threads at the end. This allows you to push it in, then spin it once or twice to engage a couple of the threads. The threads are there simply to keep the user from inadvertently pulling the arm out during use. So the arm is "virtually" a pop-in design, but engaging a couple of threads is suggested.
Saddles:
Callaham's saddles are designed from original pre-CBS saddles, with some improvements. They've slightly lengthened the string slot as compared to pre-CBS saddles, so that the strings will not bind and bend against a sharp edge before going over the saddles, which reduces string breakage. Fender's current production saddles have their slots moved too far to the rear, causing string breakage and loss of downward pressure on the saddle, hurting both sustain and tone.
There is a commonly-held belief that pre-CBS saddles were hardened, but Callaham states that every pre-CBS saddle they've tested measures on average only 50 Rockwell B. Callaham has chosen steel with a hardness of 95-98 Rockwell B for their saddles. Further, the steel work-hardens in the making of the saddle and is well over 115 Rockwell B where the string crosses.
DOWNLOAD A COPY OF OUR CALLAHAM TREM BLOCKS DATA SHEET AND COMPATABILITY DATA SHEET TO CONFIRM WHICH ONE YOU NEED.
HERE IS A COPY FROM CALLAHAMS SITE OF THE STRATOCASTER BRIDGE COMPATABILITY SHEET
In the Kit: