91 Chevy 350. Keep efi/throttle body or swap to carb

[Bridgeman57]

Picking up a 91 350 with 163k original miles. Stock engine. 4L60 tranny for $500. It will be going into a 57 Chevy 3600 thats converted to 4x4. Not sure to keep it fuel injected or swap to carb. Is it a pretty simple swap? Just manifold, carb, fuel reg and other little things? I know fuel injection has its benefits. It comes with the whole computer and harness. Also should I use the 4L60 or toss it and get a tb350 or 400?
Thanks, anything helps

[b454rat]

Being a 91 it would have a 700r4. TBI Is a solid simple system. Just can’t make crazy power. But they make good torque.

[95 S_Trucker]

Originally Posted by b454rat

Being a 91 it would have a 700r4. TBI Is a solid simple system. Just can’t make crazy power. But they make good torque.

The 700R4 was renamed 4L60 in 1990. The 4L60E came out in 93.


I like fuel injection, but if you do switch to carb, the TV cable must have the proper linkage and adjustment or else you will burn up the transmission quickly.

[b454rat]

Technically wasn't renamed till 92....

1988, 89, and 90- 700r4 trans. Nothing changed

1991, 92- Name changed to 4l60. No changes were made from the 700r4.

1993- first year for the 4l60-E. In its simplest terms, it is an electrically controlled 700r4. No PWM. 11 pin connector

1994- NOTHING changed between 93 and 94. Transmissions are directly interchangeable. No PWM. 11 pin connector

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.

1997 (one piece bell housing)- Identical to 1996. Direct swap. 12 pin connector.
1997 (two piece bell housing)- Identical to 1996 EXCEPT the addition of a transmission ground wire in the harness. This was done to address poor transmission grounding issues on the previous models. Can be interchanged with the 1 piece bell housing, but the ground wire should be added to the harness if you are using the 2 piece. 2 piece bell housing models also had hardened sun shells to address the sun shell fracture issue common to the previous model automatic transmissions. Identical in fit, function, and design, the material just changed. 13 pin connector.

1998- Identical to 1997 2 piece bell housing.

1999-up Identical to 1998 and 1997 2 piece bell housing

[b454rat]

If the TV cable isn't friggin perfect you'll fry the tranny. Shift points be screwy, pretty much a PITA...

[Bridgeman57]

Thank you! And if I keep the stock efi I’ll have to upgrade my sending unit and fuel tank? I might keep stock tank to save money (for now) and upgrade later

[95 S_Trucker]

Originally Posted by b454rat

Technically wasn't renamed till 92....

1988, 89, and 90- 700r4 trans. Nothing changed

1991, 92- Name changed to 4l60. No changes were made from the 700r4.

1993- first year for the 4l60-E. In its simplest terms, it is an electrically controlled 700r4. No PWM. 11 pin connector

1994- NOTHING changed between 93 and 94. Transmissions are directly interchangeable. No PWM. 11 pin connector

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.

1997 (one piece bell housing)- Identical to 1996. Direct swap. 12 pin connector.
1997 (two piece bell housing)- Identical to 1996 EXCEPT the addition of a transmission ground wire in the harness. This was done to address poor transmission grounding issues on the previous models. Can be interchanged with the 1 piece bell housing, but the ground wire should be added to the harness if you are using the 2 piece. 2 piece bell housing models also had hardened sun shells to address the sun shell fracture issue common to the previous model automatic transmissions. Identical in fit, function, and design, the material just changed. 13 pin connector.

1998- Identical to 1997 2 piece bell housing.

1999-up Identical to 1998 and 1997 2 piece bell housing

We’re splitting hairs now. It was renamed in 90 for he 91 model year.

[Second Series]

The '91 has the DRAC integrated into the gauge cluster, so you'll need that, or get a DRAC module from a '92-'96 Truck or Astro, or aftermarket.

[b454rat]

lol read it again and saw 91/92. Thought it said 93..