thinking: 350 tbi to 454 tbi??

[Drunkcanuk]

rather than re-edit my last post, lets reframe this…

if i were to find a donor 1992 k2500-454/auto;
Is it safe to assume it runs the same ecm as my truck?

I will look again at that injector chart (thanks) to see what years used the same injectors;
I was hoping that if i could find an engine which is mechanically correct for 1992 that I might be able to identify which parts would need to be changed to match my truck’s model year;
In the hopes that I might make this truck seem like a factory built rcsb k1500 454 truck.
(should i decide to go this route)

I'm pretty sure the ECM is different, as guys have problems switching to a 350 from a 305 until they switch them.

Check out the EBL Flash 2. It's a factory ECM that has been modified to be able to be programmed. If you have the ability or know someone who can tune, it may just be the thing you are looking for.

 

[unruhjonny]

i had understood that ecms of this period used a memcal “chip” (sometimes referred to as an eeprom);
that chip could be swapped out, and was in essence what had the tune flashed to it;
I understood that a given model year/platform/engine family all used the same ecm - but with a different chip specific to the engine/transmission combination.

I would think the 305 & 350 would use the same ecm, but a different chip;
i had guessed that a 454 used the same ecm as the small blocks.
maybe i was wrong.

 

[PlayingWithTBI]

I understood that a given model year/platform/engine family all used the same ecm - but with a different chip specific to the engine/transmission combination.

Not really, the ECM/PCMs were changed based on engine and trans configurations such as, 1990 and 91 454SS used the 1228747 to control the TH400 trans. They never put a 700R4 (4L60) behind a BBC or a C/K2500 HD+. When they went to the 4L80e, they used a different PCM. The 7747 can be upgraded to a 7427 but, you have to change some pins and run the 28pin chip from the 7427 instead of the 24 pin from the earlier ECM. That's why the have multiple ECM/PCMs and hundreds (maybe) of .bins

 

[Firewood truck]

As someone that is about 75% through a L31/TBI swap using the GMPP intake, it's been a bit of a PIA. At the end of the day when I get it all sorted and can put the truck back to work, it might be worth it but the GMPP intake just leaves a lot to be desired in terms of working out all of the little details to make it run.

 

[unruhjonny]

As someone that is about 75% through a L31/TBI swap using the GMPP intake, it's been a bit of a PIA. At the end of the day when I get it all sorted and can put the truck back to work, it might be worth it but the GMPP intake just leaves a lot to be desired in terms of working out all of the little details to make it run.

interesting...
I would greatly appreciate it if you might do a write up of your first hand experience.

 

[unruhjonny]

Not really, the ECM/PCMs were changed based on engine and trans configurations such as, 1990 and 91 454SS used the 1228747 to control the TH400 trans. They never put a 700R4 (4L60) behind a BBC or a C/K2500 HD+. When they went to the 4L80e, they used a different PCM. The 7747 can be upgraded to a 7427 but, you have to change some pins and run the 28pin chip from the 7427 instead of the 24 pin from the earlier ECM. That's why the have multiple ECM/PCMs and hundreds (maybe) of .bins

I continually get thrown off because you keep citing different model years.

I am trying to keep the theoretical conversation to a singular model year - not a hodge-podge of different model year parts;
That year, to be amply clear, is 1992.

I didn't realize that the ECM in any way affected the transmission - I had thought that they stood separate from engine management;
I know many people who have swapped in four speed automatics into earlier three speed automatic vehicles, and I do not recall mention of any computer - maybe that's because they were non-"E" transmissions(?).

Ok, so I just looked at the pdf of my truck's RPO code, MD8 = 700R4/4L60
Since mine is a 1992, that's probably a 4L60-E;
Which brings us back to the ECM...

New side question, if the 700R4/4L60 has been used in musclecars for decades, why couldn't it work behind a 220hp 454?
Have people tried here and failed?
I mean, if the transmission is a part of the ECM equation, then eliminating that as a variable suggests one might be able to do an engine swap, with just tweaking the tune to accommodate different injectors... or maybe the pulse for a 350 injector would be sufficient to run the larger injector on the 454...

 

[PlayingWithTBI]

I just looked at the pdf of my truck's RPO code, MD8 = 700R4/4L60
Since mine is a 1992, that's probably a 4L60-E;

No, the 700R4(4L60) is not an Electronically controlled trans (the 4L60E is) but, the ECM controls the TCC (Torque Converter Clutch). You'll need the TV Cable to control it, or you'll smoke it in a matter of minutes. BTW the 454 Throttle Body didn't come with the linkage for that either so, you'll need to fabricate the conversion too.

I know many people who have swapped in four speed automatics into earlier three speed automatic vehicles, and I do not recall mention of any computer - maybe that's because they were non-"E" transmissions(?).

Are we talking about them swapping into trucks or lighter weight cars? Was the 700R4 modified to withstand the torque a 454 puts out? That's why GM didn't do it.

I continually get thrown off because you keep citing different model years.

I am trying to keep the theoretical conversation to a singular model year - not a hodge-podge of different model year parts;
That year, to be amply clear, is 1992.

Sorry, I was confused when you said "If I was to do a 454 swap (assuming I use all correct for my trucks model year senders and throttle body) what is different?" on your 1st post. Multiple years are "Correct", it's just engines and ECMs aren't.

 

[Firewood truck]

interesting...
I would greatly appreciate it if you might do a write up of your first hand experience.

I have a thread in the engine performance section.. It' nothing to get too excited about, my truck is an old farm truck that I'm using as a firewood truck ( hence the screen name). I got the L31 long block cheaper then a set of pistons would have cost, so I decided to use the Vortec long block including the accessory drive and would figure it out along the way. It was a horrible plan but it was the only one I had.