I have 1988 K5 with a 5.7 350 Tbi and a 700r4. The engine through a rod so I’m rebuilding a 350 out of a 1973 C10 pickup with a quadrajet carb. I want to get rid of the computer for the the throttle body but I’m not sure if it will mess with anything on the gauge cluster. Has anyone done a swap like this and how hard is it to delete the computer?
CK5
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1988 K5 TBI to Carb swap
- Thread starter DKrc17
- Start date
I would suggest keeping the TBI. It is reliable and well proven. Going to a carb, although simpler, is almost a step backwards. Unless you are building for big power, because the TBI can't really handle it . You can get a adapter to run the throttle body on a carb intake. Also you would have to get a different flywheel/flexplate because 88 motors had a one piece real main .
I have had nothing but problems out of the throttle body on mine. Before the motor through the rod I was replacing Tbi components every couple months. Idk if mine is just a problem child or if the previous owner messed with something because all the wiring under the hood looks like it’s been messed with at some point.
I love my TBi. It always starts, runs on angles and works good at altitude.
Another vote for keeping the TBI. That being said, the guages are separate from the computer. You will need a different distributor.
Martin
Martin
Your speedometer is probably electronic, run off a vss. You will need to make modifications to the 700r4 to work w/o the computer. Look up Bow Tie over drives, they have info and also sell the modifications. I didn't like the garage door spring they use on the throttle valve spool in the valve body so i changed for a stock one. I also didn't care for the generic adjustable tv cable they use in their kit's, I ordered one for 91-93 Implala for my truck. Also had to use the Sonnax tv spring to maintain proper tv tension and get wot with a q jet. I tried the throttle linkage adapter/s finally went with stock location and the Sonnax spring
www.sonnax.com
If you keep the electric fuel pump you will need a fuel pressure regulator, pref with a return to tank.
TV Cable Corrector Kit - AS1-01K
In most GM and Ford transmissions with cables, including GM TH200, 200-4R, TH200C, 4L60 (700-R4) and Ford AOD, AXOD, the throttle valve cable pulls out of ad
If you keep the electric fuel pump you will need a fuel pressure regulator, pref with a return to tank.
i sure your right for the squares, the gmt400 had electronic, I sometimes can't separate those 4 years in my memory.
1988 V series Blazers, Jimmys, and Suburbans still used an NP208. They switched to the NP241 in 1989, but the first year still used a mechanical speedometer. That is why people seek out the '90-'91 V series NP241 for LS swaps.
Martin
F-ingrob
Wheres the mud
I swapped my 87
Hated the TBI lack of power but loved the injection
I do not miss the old TBI
I left the computer in place but cut all the wires out of the engine bay harness
I use a fuel pressure regulator that has a return and have the fuel pressure set at 5 psi
I also run a Holley 650 double pump as they are better off road than a vacuum secondary
If and When you do yours you need to keep the oil and water sender wires.
The rest you can get rid of
But you will have to find a 12 volt keyed hot lead for your coil
Hated the TBI lack of power but loved the injection
I do not miss the old TBI
I left the computer in place but cut all the wires out of the engine bay harness
I use a fuel pressure regulator that has a return and have the fuel pressure set at 5 psi
I also run a Holley 650 double pump as they are better off road than a vacuum secondary
If and When you do yours you need to keep the oil and water sender wires.
The rest you can get rid of
But you will have to find a 12 volt keyed hot lead for your coil
How about just sourcing a new underhood harness from somebody here and swap it in? I know people get in the mood to change everything to be sure they got the one thing that was wrong, but the more extreme the changes, the more problems there are to sort through with the new setup.
Best bet I think would be an electric pump to prime the carb and then a quadrajet. Best bet of all worlds.
It would pretty much eliminate the heat soak, vapor lock and cold start problems with a carb. So you would end up with all the power of a carb with no or very few drawbacks.
It would pretty much eliminate the heat soak, vapor lock and cold start problems with a carb. So you would end up with all the power of a carb with no or very few drawbacks.
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