engine swap and computer swap in 1997 xj?

[TooTall]

Hey guys i no this is comanche talk but i have a ? for a 1997 cherokee i bought with a cracked motor swaped the motor out of my 1996 cherokee in it and noticed fuel pump wasnt kicking on so replaced relay and walla! so need new one of those....but also noticed heater core is leaking so how hard to replace?figured when engine blew cause some dumbass replaced with water only that is why heater core went out.but also had no computer on it so i put in my 1996 and seems to work fine ...but my 1996 was a automatic and this is a standerd does that make a difference and also no dash needles moving but all lights etc..work???? :doh: :bowdown: