Hello Jeep heads. I am new to this forum, and have some questions. I have had a 95 Wrangler in the past, and I just bought a broken down jeep. It is a 1990 Wrangler YJ with the 4.2 with standard Trans. Are there any engines besides the 4.2 that will easily interchange without having trans and transfer case issues? Does the 2.5 or the 4.0 bolt up to the trans? Will the whole 4.0 engine and trans combo have issues lining up with the transfer case? Or should I just continue to look high and low for a 4.2. (not finding any) Thanks