[zmaster]

I would like to know if this is possible/practical? That is to (when the time comes) replace my old 4 cyl engine with a V6 engine.

 

[alltrac165]

Anything is possible, just takes money

Things that will fit-
Nothing that I know of...

Things that need to change-
Motor mounts
Tranny
Engine(duh)
Possibly the fuel pump
Exhaust
Computer
Engine wiring harness

Not too practical in my mind if you just want a little more zip. You could get a good bit more poop out of the 22RE for the time and money spent on a V6 swap.
The usual suspects there-
Port the head
Headers and exhaust
Cam
Intake
ARP rod bolts
Balancing

Or, you can get the 22RET(turbo motor set up) that can be tweaked to get a good bit of power as well. Stock, they are not too far off the 3VZ, I think. You'll still need a stronger turbo tranny and computer, but at least it's basically the same engine.

These are just my opinions, ymmv.