Yes its 1-1/8th. Length varies a bit by size. All new forks come with a 10" or so long steerer tube.
Procedure is to either measure the old one and cut to length or install the lower crown race. This will need to be pounded down with a special tool until it is absolutely flat and even with the fork crown. Then install the lower bearings, put the tube through the head tube, install the upper headset cup/bearings add spacers to preference and stem. Then make a mark in marker at the top of the stem. Remove it all but lower crown race. Measure 1/8th or below the stem line and cut. Install the star nut.
The above is just for fit you don't have to tighten the stem down. Be sure the star nut is at least 1/4" to 1/2" below the top of the steerer tube. Then install your headset as you normally would, the spacers, and the headset cap as well.
Tools needed:
Bi-metal hacksaw
Vice
Half round metal file
Mallet, or large hammer
Threadless saw guide
Starnut setter
Crown race setter
Crown race puller
The last 2 can be optional, but you risk mangling your crown race. The crown race setter can be made with a 10" 1-1/4" steel/iron pipe, the removal of the crown race can be done CAREFULLY with a hammer and long flat head screw driver.
You may want to let your local shop (probably not Dick's unless you're lucky enough to have a good tech like me or David there) do it.
Incidentally
Marzocchi 44 tst 2 That's the fork I just bought for my hard tail. Its 120mm, and I would go anywhere beyond that for the Coil Ex. Seems to be a great mid level fork, but its been raining on my days off consistently so I haven't tested it yet on real dirt.
David. Feel free to add or subtract anything I said here. :thumbsup: