Okay I have a 99 2500 LD that originally had the LQ4, but its done so I am installing an LQ9 in its place. I know there is a difference in the length of the crank between motors 99-00 and 01 and up are a different length. Will the LQ9 just bolt up, or do I need an adapter? Also, when I had my Lq4 apart I was expecting to see dished pistons, but they were flat topped. Were the 99's different? It has a 4L80E btw.

 

I think the LQ9s have a beefed-up bottom end but all the same stroke and everything.

 

You will need a crank spacer to space the flexplate out enough for the 80e. Never heard of an LQ4 with flat top pistons regardless of year model.

 

Where would I go about finding a spacer like that, the dealer?

 

Yes..

 

Alright, so the new motor is in and is running great so far. Couple of things though:

The engine did not come with a computer so right now I'm using my tuned computer for a 99 truck on a 04 engine. Weren't the computers used in the 03 and up trucks a lot better than the ones from 99-02?

The check engine light is on, and I haven't had a chance to pull the codes yet, but I think its just gonna be some random codes the computer is throwing because it doesn't have the right computer.

Also, my truck is now slower than it was before the engine swap despite putting in an LQ9 with 45 more hp than my previous engine. Again, I think all of this has to do with the computer, but I'm not positive. I don't think its really affecting anything, but I did have to use my old TB to hook all my cables back up. The TB on the LQ9 would not work so I just pulled my old one off the LQ4 and bolted it on there.

 

get a new tune. tune out the EGR and have them upgrade your operating system to an 02 OS. should wake your truck up considerably.

 

Why tune out the EGR?

 

The computer shouldn't care whether the physical motor is a 1999 or out of a 2004. Physically they will be near identical. Make sure you have all the sensors hooked up and get those codes scanned.

Removing the EGR and running the 2002 computer tune will result in the best all around performance. EGR dirties up everything in the intake. The 02 computer was the strongest running version of the 1999-2002 models and it tuned well. The 2003+ PCMs have different harnesses and will be electric throttle body, which is why you should do the 2002.

 

I am about to do the exact same thing, and I remember someone saying the hardware of the 02 PCM is different than the 99. Who does the reflashing 99 software with 02 software?