If i change from a v6 to a v8 on my 93 mc do i have to swap out the computer?

vacuum brake booster questions only> out and in.
the manual says remove MC first , just that.
the MC 2 lines go to the ABS modulator. sure.
I guess you mean how to remove those 2.?

bleeding it later with scan tool bleed mode is best.
per FSM

https://eautorepair.net/Marketing/Default.asp

3.9L V6
LEAKING DOT4 IS , NOT ALLOWED EVER
BUT YOU ONLY SAID THE WORD LEAKING, NOT WHAT IT LEAKED
WE DO (vacuum leak down) TESTS ON THE BOOSTER BEHIND
THE MC, AND THERE IS NO FLUID IN THE BOOSTER ever.

.SO fluid LEAKS ARE ALWAYS MC BAD, END STORY.
OR LINES RUSTED TO mc OR LOOSE LINE FITTINGS TO IT.
THE BOOSTER IS ONLY A VACUUM DEVICE,.HERE. PURE!
VACUUM BOOSTER ASSIST.
fix leaks first, find the source an fix it first.
bleeding is JOB last on brakes.
and last last is silly lamps, that many need reset.
and ABS will now have a ton of air on its inputs and hard to get out.
but i bet you knew that and to read the service manual
the factor did use pressure bleeding to make the car new.
(fast and sure ) my jeep has ABS bleed cycling mode.that helps.

the MC rear seals love to fail and leak flue
the inside MC seal fails is never fun to find. and unbalance brakes is never going to make ABS happy here if true.
leaking mc is really great thing,it yells I AM BAD
unlike inside wear.
no 30 year old MC is good. so there is that too.

If the engines are the same year, drive train (Auto or Stick), CC, and came out of the same make/model of vehicle you can usually do the swap. However, It will be an 'Engine Only' swap.
The main difference between the 4x4 and the 4x2 is the transmission layout. The 4x4 has an extra section of gearing on the drive system called a 'Transfer Case'. This is where the split to front and rear drive comes from.
If you remove the engines from the transmission housing like you were changing a clutch you should be able to take one engine out and drop the other one straight in.
On some set ups you can leave the transmission in place and unbolt at the engine end of the Transfer Case but to be honest removing just the engine is easier as you don't have to wrestle with a bigger, longer and heavier lump when the transmission is still fitted.

If you're asking if you can swap them, no. Not without changing the entire wiring harness, transmissionand computer.

If the computers you fitted are from a donor vehicle they probably have the coding from that vehicle and will either need recoding to match that of the car they are now fitted into or will need decoding so they will work regardless of the immobiliser code.

I suggest you spend a few hours with the car and the wiring diagram and if every part of the new installation double checks ok it will be time to contact a specialist for more info.

you would need to change a lot of stuff to do a swap like that computers pos trans exhaust pumps raid front springs maybe more

the 2000 s-10 came with optional engine the 4.3 LT V6 262 engine should bolt right in -- rear is fine but u will need all the electronics for engine and trans -the trans bolt up is different from the 4 to the 6 engine bell housing ,clutch ,slave etc the trans itself should be usable if u get the proper bell housing

I can't give you direct knowledge, from having personally done this swap before, but I can offer you that the 1990 Cavalier, did have a V6 as an option.
The 3.1 Liter V6 with MultiFuel Injection System.

Of course, you're going to need the ECM, (Computer), and the complete engine wiring harness also.

yes they will swap out ,most have same sensors and all ,check the plugs on wiring harness before you swap them out make sure,im sure you can cause they both will work in there. hope to help you, thanks robert b.

YOU will have to swap tranny computer, wiring , radiator , would basically have to have a donor car