Hello,
I'm a newbie to the forum. I have a question. I have a '95 ETC. I bought a salvaged '02 ESC. It has a 275hp 4.6. My '95 is a 300hp. I am upgrading my '95 with the '02 electronics, wiring, and motor, including ecm (pcm). Question? What makes a 275hp into a 300hp? Is it electronic? Is it the engine itself? Is it a combo? Would buying an ETC ecm make the "new" engine into a 300hp rocket? Please reply if anyone can help me. I'm ready to install engine!!!!

Cams and ecm are the only things i have found to be different.
The powerband is shifted higher on the 9 motor.
The biggest performance gain will be from gearing.
Somewhere around 96-97 they feel so much slower out of the hole, but get 4-7mpg better.
A 94 ETC will just about rip the steering wheel out of your hand, while a 97 will be much more tame.
I never researched the actual ratios, just driven hundreds of north* over the years.

Are you using the old tranny with the new PCM?
You may run into problems if you do unless you update the internal electronics and maybe even the valve bodies and torque convertor.
A good bit changed between 95 and 02.

Good luck sounds like a fun project.

Thanks for the info! Another question. I have a crack on Trans casing end. It bolts on the end. Is that replacable?

I don't follow the question.
Are you talking about the pass side where the axle goes in?

I'm talking where the trans dipstick is. Is that cover replacable?

Yes it is.

Thanks! I may have other questions as I start carrying over the '02 to my '95 eldo.

I would be suprised if you didn't.
Good luck.