YJ to a TJ, no
No, it will not.
No, they are different
No, the spacing is different.
no ... tj to yj doors are diffrent
Not without modification the YJ top is a little different than the TJ
Yes, that will fit just fine
No they should not fit, 1990 is a YJ, and 1998 is a TJ
No. The Wrangler has several changes, windshield width, body width, etc.
the hard tops for the Yj's will fit 1987 to 1995, but you may have a CJ, and they should fit also with some tweeking
Will a 304 engine fit in a 1998 TJ jeep wrangler?
yes
yes, all cj7 doors and hard tops will fit jeep yjs