Hi and welcome to our world!
First, the biggest wheeling advantage that our little trucks have is their size and weight. Even a 4-door "TracKick" can get through all kinds of places that a Cherokee or other mid- and full-sized 4x4 can't go - with a little modification. Shoe-horning a 350 Chevy engine into a TracKick wipes out the weight and maneuvering advantage on the trails and the rocks. It might be useful in a mudder, though I can't imagine a 4-door mudding TracKick...
I can't recall ever running across a TracKick with a 350, but I have seen several 350s and a 455 in Samurais. All of them were well-executed projects that the owner seems reluctant to wheel as hard as the rest of us - with the exception of the 455 owner. His night run at the 2002 ZookiMelt was quite entertaining carnage-wise
I guess what I am trying to say is that less engine and more suspension/drivetrain work is what you need to consider.
The current trend for TracKick lifts is the Solid Axle Suspension (SAS) mod - available as a kit or by shade-tree mechanic methods. Shade-tree IFS lifts have been done and one vendor is working on kit.
You might do a search for
SAS or
IFS lift here at zukiworld.com, at Zuwharrie.com, Zukiworld.com or (shudder) Pirate4x4.com.
Finally, I have actually wheeled all my trucks - including the stock '93 4-door on the Green trails at the Badlands - and drove them 450 miles home in one piece. Naturally, the Samurai gets wheeled a bit harder that the others...