4.0 crank bolt threads

[oakesmi2]

Ok, so I searched around and I found that 4.0 cranks have 1/2-20 threads. With all the changes the 4.0 engine saw over the las 7 year of it production, I wanted to confirm that they did not change the threads on it along the way?

[5-90]

I'm reasonably sure they did not - that would have required a change to tooling. The head & main cap screws are probably still 1/2"-13, the manifold screws are probably still 3/8"-16, and the like as well.

For instance, the Small Block Chevvy didn't really "go metric" until, I believe, the fourth-gen SB350 came out - since they made other changes to the engine design as well, it was a good time to change tooling over while they were about it.

ChryCo was building a legacy AMC design, and Dr. Z had probably been planning to EOL it for some time before the end of MY2006. So, I doubt the tooling would have been changed (part of this reasoning for EOL-ing the 6-242 was that it would have cost more to renew the tooling than to refit to produce another engine. As well as complaining about meeting emissions standards, and crash safety standards, and all that rot.

(If the inline six is so bad for crash safety and for emissions, why has BMW been using the thing for the last fifty or sixty years, and why did GM bring it back in Vortec trim - coincidentally, with a 242ci displacement?)

[oakesmi2]

Ok well I confirmed it last night the crank/harmonic bal. bolt is 1/2-20.