I've done MANY ranger motor swaps....I've pulled out a carb'd I4, put in the EFI 2.9, I've pulled out a carb'd 2.8, put in the EFI 2.9, right now I'm in the middle of a 302 swap!.....pretty much it's ALL plug N Play., to put an EFI in an older Ranger, I gotta change alot of wires to get the gages and such to work, and to get the plugs on the firewall to work. I've had to take the motor mouns on the motor, and slightly modify them., I also cut the pins on the mounts off, cuz thoses ONLY line up to the original type of motor.

BUT, if ur swapping different motors, but the same year, there's NOTHING to it!, don't be scared, it's easy!