Absolutely possible...

Youd need the engine (duh), ECU, Igniter Unit, and Vacuum box...

Theres some wiring involved but its should be fairly simple and straightforward.

Also helps that you have a 5 speed as the auto trannys ARE different....

 

whats a vacuum box?

 

The one circled is the vacuum box:

 

now how about a 5-speed and a C27 into a 87? what else do i need to swap the tranny?

 

^ yeah the 5 speed would be the best bet since the 2.5 Auto needs a signal from the 2.5 ECU for lockup....so you COULD keep a 2.5 auto, but it may never lockup :sadwavey:

A 2.7 auto could theoretically be swapped in too so long as you wired up the TCU as well...

 

hoow much does a an ecu, vacuum box, and an igniter unit usually cost?

 

You can go to the junkyard and pull them out from there. Look for a 88-90 Legend.