Jeep Strokers

The 258 bore is smaller than the 4.0 combustion chamber.

Plan is to taper the bore above the piston top ring @ TDC
out to meet the 4.0 diameter.

Without pulling the engine - is there a tapering tool
that could be set to perform the job correctly -
rather not go after this with a die grinder & eyeball.

I haven't seen any special tool for that. The few times I have done it was on a bare block (non-jeep) on engine stand. I just used dyekem on the deck and bore, scribed the head gasket and measured the depth to the first ring and started at it. With enough tape and rags and a vacuum you should be able to do this with with a die grinder and a carbide burr and finish with sand paper.

~Alex

You should also put a little grease in the space between the piston and the cylinder wall when you grind it.

~Alex