TBICHIPS.COMS Frequently Asked Questions

I have found that buying most of the parts brand new from www.gmpartsdirect.com nearly as cheap as buying replacement parts from your local autoparts store.  So I have provided the GM part numbers as I answered these questions.

Q1. Can I replace my 4.3 or 305 with a 350 V8?

A1. This has to be the most common of them all. This is an easy swap as long as proper preparation and planning is used.  All the accessories/brackets and wiring can be used on the 350.  4.3L V6 guys will have to add a distributor and exhaust manifolds (headers) to the list but here are the basics to keep TBI happy.

1. You need a TBI friendly 350.  Look at my recommended modifications page to see about cams and such for TBI friendliness.
2. Computer wise.  The S10 guys should change the computer to a 1227747, 1228747 or 16146299 computer which all came with the V8 engines.  It should plug right into the S10 harness.
3. Then the hardware that you need to change is the injectors GM Part number 17112493 5.7L TBI injector, GM Part number 17111784 7.4L TBI injector (1988,1989,1990). Injector choice will depend on hp you build that 350 for.  Next, you will need to change the knock sensor GM part number 10456288. Finally you should change the electronic spark control module GM part number 16128261 since they are calibrated to the displacement of the engine and using one from a smaller engine could cost you some horsepower since it will be more sensitive.
4. Lastly the chip,  I will do what I can to make you a chip that will run your engine and the success of you swap will depend on how well you followed the first 3 items.

Q2. Can I use long tube headers and true dual exhaust on my TBI equipped vehicle?

A2. Yes you can.  When you exceed about 12" of pipe from the head to the O2 sensor, you will have troubles getting the stock O2 hot enough for proper operation.   This can be overcome by using a heated 3 wire O2 sensor for a 95 S10 4.3L V6 GM part number 25312179 or Walker AFS-74.

Q3. I have changed my gearing in the rearend.  How do I correct my speedometer?

A3. Someone sent me a link for this website that I think would be helpful in fixing that problem. http://www.transmissioncenter.net/speedometer_calibration_______va.htm

Q4. What spark plugs should be used with Vortec heads?

A4. Nobody actually asks this question but they should.  TBI spark plugs are shorter than the ones that come in the Vortec motors. Use an AC R44LTS and gap @ .045 or a Rapid Fire #8 gapped @ .035.

Q5. Can I remove my Air pump?

A5. Yes you can.  It won't set any codes in the computer system.  I do however recommend replacing the Air pump with an idler pulley to prevent some belt issues that plagued me.  GM happens to make one and the part number is 10129569 and is $40 shipped from GMPARTSDIRECT.COM

Q6. How do I wire up a 3 wire 02 to replace my 1 wire 02.

A6. Using a 3 wire for a 95 S10 4.3L TBI  GM part number 19178959(I now use Walker AFS-74 because GM raised their price over $20), wire the dark colored wire usually purple to the computer and the other wires to a ground and 12v ignition on HOT.  A relay and a 10 amp fuse would be nice too. Also on the wiring  connector C is the one for the computer and A and B are for the 12v and ground. I now carry this O2 sensor in my ebay store to help you get the AC Delco version as cheaply as possible as I really have had too many issues with the Bosch units sold in most auto parts stores. Use this link for 02.

I now sell the O2 sensor with a pigtail adapter to make plugging it into your wiring harness much easier.

Don't hesitate to send me an email at sales@tbichips.com asking your question and I will start adding them to this list.