I have a 99 Chevy Malibu that has a bad nock. I wan more HP out my motor and I know I have to change the motor. So I was thinking about putting the 3400 in the car. But need to know how much wireing I

Sounds like you big end is on its way out.

So you have a '99 Malibu. Any 3400 should plug and play in that car. Just double check the sensors as you do the swap. Usually I already know that all my sensors in my motor were good and unless you hear the new one run you cannot be sure. I swap all my sensors to the new motor and once it's running I put in the others one at a time. If they work then you know you have good spares, if they don't I toss them on the spot.

Yah the 3100/3400 are alright for power. There are better swaps but this is a good start to get your feet wet. If you know anyone with tuning software you could get more out of it.

I'm mistaken on one part. The injectors. The rest will plug and play. The '99-'00 were the transition between the wiring change on the injectors. Options: Put your 3100 injectors in the new 3400 if it's the new style. But new pre '00 3400 injectors. My forum is saying that the 3400 runs about 15 hp less on the 3100 injectors. Give the fueling a bump with a programmer and you'll get it back.

Thanks for the advice and now its time to find my motor and don't car