1997 4.3 swap questions

[skylark]

Oh, and Charlie, I wasnt putting you down at all. It was what I had in mind for that truck too.

No offense taken! Your engine build is going to be really cool.

 

[TheTitan97]

So the 95 5.7 motor won't hook up to my stuff? Is that what your saying? I literally only know very basic things about this stuff, up until this truck iv only had my old k5 blazer and only really worked with old carbureted engines, so I apologize if I ask something dumb lol. And I agree even though its kind of gutless the 4.3 is a great little engine mine has 250k miles on it and besides my fuel pump issue causing it to start funny the engine runs and drives great and sounds great. But I need some more power id like to be able to haul a decent sized trailer every so often. And your story matches up with what most people are saying about building up a 4.3

 

[TheTitan97]

Okay I just saw ur post skylark, I'm getting the entire suburban, so would I be able to swap the wiring harnesses out of it as well? Would that allow things to work together?

 

[skylark]

The 95 will physically drop in once you change the frame side engine mounts to V8 mounts. The wiring and fuel requirements are completely different. A lot changed between 94-95 and 95-96 because of the dash changes in 95 and OBDII in 96. Just some examples off of the top of my head between the 95 and 96, 95 is a basic speed density computer system, that has a coolant temp sensor, knock sensor, throttle position sensor, idle air control motor, 2 injectors, one O2 sensor, and a manifold pressure sensor.
The 96 is a mass air system that has all of that except that it has an injection spider controlling 8 poppet injectors, mass air flow sensor, air intake temp sensor, cam sensor, crank sensor and 4 O2 sensors.

 

[skylark]

Okay I just saw ur post skylark, I'm getting the entire suburban, so would I be able to swap the wiring harnesses out of it as well? Would that allow things to work together?

Everything except for the speedometer and tach SHOULD work with the 95 gauges but the tranny is still an issue.

Tranny info quoted from: http://www.gmt400.com/forum/showthr...ces-in-700r4-4l60-4l60e-transmissions-by-year


1995- Stand alone year. First year for PWM. Has an extra solinoid to control the PWM. 3-2 shift AND TCC are PWM in this trans. Has a different 3-2 control solonoid, and a extra wire in the harness to facilitate the PWM TCC lockup. Addition of a trans mounted neutral safety switch. If you put a 95 trans in a 94, it will not recognise the PWM circuits and will go in to limp mode. If you put a 94 trans in a 95, the check engine light will stay on, and the TCC and the 3-2 clutch pack will burn up after just a few miles. If you put a 96 trans in a 95, the 3-2 clutch pack will also burn up after a few miles. 95 has a 10-15 ohm TCC solenoid and a 10-15 ohm 3-2 solenoid. 12 pin connector.

1996- 3-2 shift is NON-PWM. It was changed back to a on/off arrangement. The 3-2 solenoid was changed to a 20-31 ohm unit. The 3-2 control valve was changed to "design 2". TCC is still PWM and uses the same 10-15 ohm solenoid as a 95. You can create a 95 trans out of a 96 or vice versa, but you have to change the 3-2 solenoid, the valve body, and the separator plate. If only the 3-2 solenoid is changed (and not the valve body casting), the transmission will 'cut loose' on 3-2 downshifts (shift from 3rd to neutral, then to 2nd as the accelerator is released). 12 pin connector.

 

[skylark]

The speedo and tach problem is that in 96 and up they get their signals from the PCM, prior to that there is a unit called a DRAC that interprets the signal from the vehicle speed sensor an splits it to the PCM and the speedo. The tach info was direct off of the distributor in 95.

 

[TheTitan97]

So then what exactly would be the best way of going about this swap. Is there an aftermarket harness I could buy to plug it all in? When I buy the suburban I get everything BUT the transmission. It has had the transmission taken out. So can I swap all the wiring harnesses and buy a harnesses just to make the transmission work?

 

[skylark]

So then what exactly would be the best way of going about this swap. Is there an aftermarket harness I could buy to plug it all in? When I buy the suburban I get everything BUT the transmission. It has had the transmission taken out. So can I swap all the wiring harnesses and buy a harnesses just to make the transmission work?

I wouldn't buy what you are looking at. If you heart is set on a small block swap then I would find 97 and up (due to tranny compatability) vortec 350 and it's harness.

 

[ccreddell]

The tranny is only a problem if your swapping a tranny in. No reason he can't use the tranny that's in it. Or, did I miss something?

 

[skylark]

The tranny is only a problem if your swapping a tranny in. No reason he can't use the tranny that's in it. Or, did I miss something?

The 95 (the year of his donor) is a stand alone year meaning that if he swapped the engine and harness but not the tranny then the tranny won't function properly.