Hi iwas wondering if anyone had any ideas how to beaf up the 258 6cyl auto, its in a 83 Eagle wagon 4x4, and does anyone sell suspension lifts? about 3 to 5 inches? Or is it cheaper to swap in my 304, if it will bolt up?

I have put a couple v-8's in Eagles, not too bad a fit, but you have to be able to fabricate. As was said the 4x4 hangs off the engine, on the driverside, I made that bracket go to the bell housing bottom 2 bolts. The 5/8 head and 9/16 head ones I mean.  Need to weld and make engine mounts, the exhaust has to be invented also.  The best idea is what he already suggested, a 4.0 from a Jeep with injection. Yes it is work too, but a good way to go. SH

I'm a bit late to the party here, but here goes.
 
XJ Cherokee rear springs are a direct swap into the rear of an Eagle WAGON. So, if you find some lifted springs cheap off a cherokee (which are littering the Earth) you're set. Use a 90's Dodge Dakota soft brake line (btw - your REAR universal is the a Dodge Dakota style as well, not the same as the other 3) and '97 Olds 88 (any GM H body for that era should work) E-Brake cables to extend them out as well. That should allow you to go up to about 5" (based on what my car *looks* like) in the back without any trouble. Currently I have add-a-leafs in the back giving it 1.5" of rear lift. I plan to go another 2-3" with blocks/hangers depending on how 33x12.50 tires clear.
 
For the front, get your welder out and dream away... My "solution" is a full XJ front axle/suspension/steering swap, which is currently way stalled out. Someday...
 
As for performance, I can testify to gears and traction mods.. I have 3.54s in the back of mine (to match the before mentioned XJ front) and a Powertrax locker. My Eagle is a 5 speed (which is cheating, since my 1st gear ratio is WAY lower than an automatic car) and it will powerslide and donut in 1st as well as my 5.0 Mustang. It's pretty cool!