Clear packing tape. $1.89 roll at Home Depot.
If you can't afford to replace the parts that wear/break from age and neglect, how do you plan on affording upgrade parts? These big plans you have in your head actually cost money, I don't see a 2JZ-GTE just falling in your lap for free.
So what you're saying is, you're willing to blow money on something you don't really need, but you can't afford to replace the normal wear parts, like ball joints, tires, etc.
Let me guess, you're under the age of 21?
Haha, good points.
There is no point in putting a stick in an LS400. Part of the brilliance of the LS is the buttery smooth drivetrain. Get rid of that drivetrain, and you're pretty much changing the intent of the car. It's like these people who put stiff shocks/springs on their LS400. WhY!?
There are much better performance sedans than the LS.