V6 to V8 ECM swap question

[86k10]

I have a 1995 Chevy C1500 RCSB W/T, came with a 4.3 & 5 spd.

I recently did transmission swap to a 700R4 and now want to do a 350 swap.

My main question is as far as the ECM goes can I swap out the PROM with a 7747 out of a 1991 K1500 350/700R4? If so will the tach work correctly?

I also have a ECM from a 1995 K1500 350/4L60E. Should I get that PROM programmed with the transmission off? Or use my original one and get that programed to a 350?

My 700R4 is set up already so I won't need the ECM for that.

 

[Stokes1114]

It's much easier to turn the trans off electronically and switch to a 700s lockup strategy than to do the motor swap on a chip. Use the 95 350 4l60e pcm as it has the correct netres and knock circuitry on the memcal (chip). Then have someone program a new chip to adapt to the memcal for the 700r4.

 

[L31MaxExpress]

It's much easier to turn the trans off electronically and switch to a 700s lockup strategy than to do the motor swap on a chip. Use the 95 350 4l60e pcm as it has the correct netres and knock circuitry on the memcal (chip). Then have someone program a new chip to adapt to the memcal for the 700r4.

^^^All you would need is a properly tuned V8 memcal. The 700r4 coding exists inside the PCM it just has to be enabled and a Park/Neutal switch added and a wire run from the PwM TCC output to the 700r4s lockup solenoid.

 

[86k10]

I already have the 700r wired up stands alone from the ECM using a brake switch to vacuum switch to 4th gear switch. Working good.

I talked to TBI Chips, he said he would use the 350/auto program and just delete the transmission from it.

I think I'll go this way. Once I find and buy a complete engine assembly I'll buy the chip.

 

[Stokes1114]

^^^All you would need is a properly tuned V8 memcal. The 700r4 coding exists inside the PCM it just has to be enabled and a Park/Neutal switch added and a wire run from the PwM TCC output to the 700r4s lockup solenoid.

Exactly. This has gotta be Fast talking about his g or express vans?

 

[Stokes1114]

I already have the 700r wired up stands alone from the ECM using a brake switch to vacuum switch to 4th gear switch. Working good.

I talked to TBI Chips, he said he would use the 350/auto program and just delete the transmission from it.

I think I'll go this way. Once I find and buy a complete engine assembly I'll buy the chip.

This would be the ONLY "tuning" I would let Brian do. Anything more than that and he is worthless. L31max and I both know what his chips look like.

 

[86k10]

Out of curiosity who else does GM OBD1 programming on these trucks?

 

[Stokes1114]

Go over to the site gearhead-efi and there are quite a few. Dave W on the site can remote tune for ya. Or possibly L31max (fast) can.