The C-135, much like the C-113 & C-123 are pretty simple to work on. Just note the rods are numbered, and the numbered side goes towards the camshaft side. Just be careful pulling the front crank pulley, you can take a chunk out of the backside if you don't have a proper puller. Should be a press fit, helps to heat it up to about 400ｺ to go back on. Don't forget to put the woodruff key in the crank for the pulley, before putting the front timing gear cover on. Install the rear felt main seal dry. Don't apply oil before you install it. It will swell, and you'll not get it in.
Others may not agree, but that's fine. If the crank needs turned, I prefer to have the machine shop get the bearings. If there is a problem with fit, it pretty well narrows down where the problem lies.
If you have a hoist, an engine stand, some basic tools, and a torque wrench, you ought to be good. Don't know what you have for a service manual, but an I&T should have all of the torque specs.
Depending on what condition the clutch is in, now is the time to change it. Check the condition of the flywheel. If the clutch has been grabby, the machine shop can reface the surface while you have it down.
