Is it worth it for me to learn to do this stuff myself? (TBI 4.3L to 5.7L swap)

[PPPPPP42]

All this tuning fascinates the hell outa me, not for scraping up every last horsepower but to be able to take random combinations of vehicle and engine and GM TBI (the best fuel system ever made as far as I am concerned) and actually make them run correctly together.
I'm not afraid of EFI wiring and sensors, I managed to check continuity to the pins in the ECM connector on a '98 Cherokee when it had a MAP low input code that wouldn't go away and found that the harness had worn through and was grounding the sensor wire for the MAP (though the 5v signal and ground were fine)

At this point all I really need to do is take my 1992 K1500 4.3L 5spd and make it a 5.7L. I plan to get a stock 5.7L of the same year just to cut down on parts lookup complications down the road.

I'm under the impression that my manual transmission adds a complication and someone made it sound to me like it would be easier to have my prom in my current computer reprogrammed to 5.7L specifications (rather than replace it entirely). I also would like several emissions pieces removed at the same time and the programming adjusted accordingly.

I don't know how often in the future I would be doing this stuff though I do have a laptop lying around if its as simple as buying a connector and software and learning to use it.

I'd rather like to learn to do this stuff myself, but I may be trying to take on too much at once and possibly would be better off just having someone reprogram this chip for me. If I do learn this stuff I would probably be doing a lot more of it in the future.

Not to muddy the waters with another questions too, but I keep reading that the 4.3L and 5.7L throttle bodies are identical but have different injectors. That doesn't make any sense to me as a 4.3L needs less air than a 5.7L so I would expect the bore to be different. It would certainly save cash to be able to reuse everything but the intake if that were true though.

[1project2many]

Replacing your engine with another that was available in your truck is a fairly straightforward process. Using the V6 calibration will cause issues but since the truck was available with a 5.7 the correct calibration is easy to find.

The 4.3 does use the same diameter throttle body as the 5.7. The injectors are usually smaller so total fuel delivered is reduced. You'll need to check the injector size and likely move up to 5.7 parts. It might be easier and less costly to buy a complete used engine for parts.

[RobertISaar]

if plan on swapping engines/transmissions/ECMs a lot...... you would be best to learn how to DIY, from both an investment and capability standpoint.

[EagleMark]

There's also time to think about. All this cables, laptops, software chip burn equiptment, not to mention time and learning curve! Do you have time, money and desire?
*Warning! The 12 step EFI addiction class was closed do to everyone thinking AA was to disable checksum. *

I've got a 4.3L TBI here... well it has 4.3L injectors and it is smaller bore then 5.0L and 5.7L which are the same... so are you guys sure?

1992 4.3L or 5.7L manual probably has a 1227747 or equivlent (288?) and not the newer Memcal ECM which came in auto trucks. Pretty sure a 7747 plugs in so tuning would be a great ECM to start and learn on.

[1project2many]

I've got a 4.3L TBI here... well it has 4.3L injectors and it is smaller bore then 5.0L and 5.7L which are the same... so are you guys sure?

How much smaller? I've only seen three sizes on TB bore. 2.8, 4.3/5.0/5.7, 7.4. If the bore is a lot smaller it's probably a 2.8 TB.

[EagleMark]

So are 5.0 and 5.7L same? This one here is smaller then 5.7L TBI but does have 4.3L injectors and does not look to be ever taken apart...