Need Performance Engine Help

[PartsPlant81]

We have a 1999 Firebird in our shop with a 5.7G LS1 engine that needs to be replaced.
We tried contracting the closest Chevy Performance dealership and they were no help with information.
Factory part #'s 12554375 and 88893287
Customer is looking for info on a performance engine since the others are DISCONTINUED.
Any help you can provide would be awesome.
Thank you in advance.

[SYSTEMBOB]

did you check on the gm connect n cruise site?

[PartsPlant81]

No. Can you type out the address please?

[PartScott]

I guess the first question that I have is, does the customer want all of this to work with the factory PCM or is he okay with going to a stand alone unit? Regardless of the answer, it's probably going to be a pretty substantial job to get done.

[PartsPlant81]

I agree. He just wants to know if he can put a performance engine in. I don't think money is an issue right now.

[PartScott]

I agree. He just wants to know if he can put a performance engine in. I don't think money is an issue right now.

A wise man once told me, "for a little more time and a little more money, we can do anything".

The LS1 in the '99 operates on an ignition system using a 24X reluctor wheel, whereas all of the engines offered in the performance catalog operate on a 58X system. To operate on the vehicles existing PCM the reluctor wheel definitely needs to be changed, I am thinking the crank position sensor and cam sensor needs to be changed (which, I believe, also requires changing the timing cover to an early LS2 unit). Some engines come with the intake setup already installed where others will need an intake. The intake on the LS1 has "cathedral" style ports and the new engines have rectangular ports requiring a different intake than the factory. The throttle body on the new engines operate on a drive by wire design and the car is using a drive by cable system. Again, to operate on the vehicles PCM would require a throttle body change and the factory unit will not work on the newer intake. Newer engines have no EGR system so you will have to have custom software tuning (which I have a feeling will need to be done regardless) to disable the EGR codes in the factory computer to prevent SES light. These are the things that I can think of right off the top of my head...and mind you that I have no experience with doing this swap but as the owner of a 2000 SS Camaro, I have looked into it in the past. Your best friend will be either a shop that does this kind of work on the regular, or some hardcore internet research on some vehicle specific forums.

[PartsPlant81]

Wow. Thanks for the info Scott. Sounds like this is a road we should definitely avoid here.

[SYSTEMBOB]

https://www. chevrolet .com/ performance/ connect-cruise-powertrain-systems