Main bearing fitment issue?

[blackwind192]

Putting together a stroker build, I have a 258 crank, unknown year. Going in a 93 4.0 block.

My issue is that the main bearing on the crankshaft fits in the block, but then the sides are too wide to allow the crank to fit into the bearing due to a sort of flange on the crankshaft.

I am using a set of 4.0 bearings. Went and picked up a set of 4.2 bearings and they are the same width, but won't fit in the block.

Pics will be posted shortly.

[blackwind192]

[jasonb]

That's the #3 main bearing, put that one in the #3 journal and the others everywhere else.

[Cheromaniac]

That's the #3 main bearing, put that one in the #3 journal and the others everywhere else.

Yup. He's hit the nail on the head. That's the no.3 main or thrust bearing.
That said, the 4.2 main bearings have locating tangs offset to one side and they won't fit in a '91+ 4.0 HO block. You need main bearings that have locating tangs in the center (Federal Mogul part no. FM7211M or Clevite part no. MS-1947P).

[blackwind192]

Thanks guys. Feel so stupid right now it's not even funny. At least I can move on now!

[SilverXJ]

LOL... wrong engine for that location.