TBI or carbs?

[98chevy2500SS]

Good thing you are sticking with the TBI, like others have said, it's fuel injected (no messing with the fuel mix ratio to make it lean or richer, etc.), it's more economical, and it runs smoother. I would never put a carb in my Vortec, love the fuel injection.

 

[TacticalPrepper]

I just got done going from TBI to carb...there are issues that must be addressed ..in a nutshell ..

Fuel pressure must be knocked down to 5-7 psi for your carb ....whether you run the factory electric in tank with an external regulator or run a straight old mechanical style pump its your choice ....I personally ran the old mechanical pump as I didnt want to deal with the ECU , its oil pressure switch, all the relays etc ....then you have to address the pickup in the fuel tank..if you go mechanical make sure your block is drilled for the old mechanical pump and your camshaft has a fuel pump lobe - some dont .

Distributor you need to go to an old school mechanical HEI - no biggie .

Hopefully your tranny is not electronically controlled if you go carb or you will have to address that . My 700r isnt - so that was easy .

Its not a cheap swap but I like the whole old school setup in a newer truck idea and I like that I can upgrade in the future without computer tuning, tuners, chips etc ,,,,,

As others stated above tbi is going to be cheaper, you can add a cam , but then you have to deal with the tuning.

 

[TacticalPrepper]

I have a 1990 with 700R4. Is it electronically controlled. Or how would I figure out.

 

[89GMCJOHN]

I have a 1990 with 700R4. Is it electronically controlled. Or how would I figure out.

A 90 shouldnt be electronically controlled....

 

[98chevy2500SS]

@TacticalPrepper The 4L60E is when they started to be electronically controlled, or computer controlled, hence the "E" at the end. The 4L60E is basically a 700R4, except the 60E is electronically controlled, the 700R4 is not. The 700R4, I thought, was cable controlled.

 

[884x4310ci]

A 90 has the th700r4 the 4l60e started in 92 iirc.

 

[89GMCJOHN]

A 90 has the th700r4 the 4l60e started in 92 iirc.

"
In 1993, an important change did occur and that was the conversion of the hydraulic logic shifting system over to an electronic one. Mechanically, the transmission's power transmitting core remained the same, but the valve body and actuation system for the clutches, bands, etc. became controlled by electronic actuators and solenoids. A Vehicle Speed Sensor (VSS) was used as the primary feedback sensor, which fed the PCM or ECM (vehicle powertrain computer) the data to make shift decisions. The engineering of this system is not regarded as a complication, but an elegant simplification and further improvement to this transmission. This version is called the 4L60-E (or Early 4L60-E for our purposes).

In 1997, the 4L60-E began to be released having received a redesigned case. This is the Later 4L60-E, discussed here."

 

[884x4310ci]

OK the change was 93. I also knew about the later changes. The big electric plug is not the same.
found that out the hard way.

 

[c1500deathtrap]

I have a 1990 with 700R4. Is it electronically controlled. Or how would I figure out.

just look for a throttle valve cable. the 700r4 has one, the 4l60e does not.It'll be on the throttle bracket on the tbi unit below the centerline of the throttle shaft.

 

[TacticalPrepper]

@TacticalPrepper The 4L60E is when they started to be electronically controlled, or computer controlled, hence the "E" at the end. The 4L60E is basically a 700R4, except the 60E is electronically controlled, the 700R4 is not. The 700R4, I thought, was cable controlled.

Ok so since my trannsmision doesn't require a computer. What all do I need to do to put my 400 sbc out of a 1975 suburban in my 1990 k1500.