personally, i'd build a megasquirt and use speed density; i'd use a single o2 sensor, but still make it sequential. but i like pain.
agree the LS1 pcm is a very nice one, with custom operating systems available, and tons more tuneability.
there's also way more knowledge about it, thats the BIG thing. the more i dig into it, not many people truly understand the LT1 pcm. there are some very weird behaviors you run into, and you're completely on your own.
i found a value way in the middle of the range for the iac keep-alive that makes the car die off idle. i've found that blm cells 16-18 are actuated by the canister purge system. i also can't get around the fact that i have one o2 sensor further downstream than the other, and the lt1 pcm HATES it. weird stuff. nobody studies them because 99% of the serious chev FI guys have gone to the LSx platform.
when it comes down to it, the lt1 pcm is lacking a lot of important variables that matter a lot in driving range once you start modifying it heavily, including transient fuel (pump shot), closed loop behavior (o2 delay times, etc), and lean cruise.
funny thing is, the LT1 has a transient fuel map, but nobody has figured out how to modify it yet. i can tell you how to turn it on or off, but not how to tune it.
it has some sort of weird o2 compensations in the LT1 pcm too, to deal with exhaust design.. the F-body runs a 425 millivolt o2 swing point, but the Y-body runs 381... makes sense? no, not really.. always wondered whats up with that
even the ability to run a highway lean cruise mode almost makes me want to swap pcms. that kind of shit is getting really important, for people daily driving big displacement cars with high gas prices. there's just no good way to do it with an LT1.
of course there's another big glaring limitation; you can cam the thing to make high end power all you want, but rpm is a 16 bit integer, and it wont rev out that high. it runs out of data.
