I was trying to compare 2 pictures on ebay of a 250x head to a 350x (3 wheeler) head, I noticed some differences, but it looks like the bolt holes lined up, I do see lots of similarities between the two. Does anyone have a 350x head off and a 250x head they could put on to see if everything lines up?

This mod would be nice for a few reasons. I think the 250x uses a bearing cam. 2. there should be lots of 250x/300ex heads out there since many people are putting 350x motors into their 250x's.

A single head pipe exghaust would have to be fabricated, I don't know if the carb boot is the same or would line up, I'm also not sure about oil flow.

Can anyone help here?

 

The heads won't interchange, but the whole topend can be made to fit.

 

What exactly doesn't line up?