Is it legal to change a 4 cylender into a 6

  • 1997 CHEVROLET S-10
  • 150,000 MILES

Will it be able to pass smog. Is it possible to change a 4 cylender into a 6 cylender and have it pass smog. Will I be able to register it with DMV. I just want to know if it is possible and if I could register it with DMV. I just want to change the motor from a 4 to a 6.

Do you
have the same problem?
Saturday, July 27th, 2013 AT 7:39 PM

1 Reply


It is not practical to do that. The cost in labor will be much more than if you just go out and buy what you want. Besides the engine, you will need a different Engine Computer, engine wiring harness, stronger front springs, and larger radiator. Other potential differences include the flex plate, transmission, fuel pump, engine mounts, Body Computer, and instrument cluster.

The front brake pads and calipers will need to do more work since the front-to-rear weight distribution will be different. That might be done with larger front calipers and pads. For sure the pressure-differential valve will be different. There can be a dozen different part numbers for one truck model depending on options including with or without air conditioning, engine weight, etc. Failure to use the correct valve could result in easy rear-wheel lockup or failure of the rear brakes to do enough work which could cause the front brakes to overheat and fade. Insurance investigators and lawyers love to find things like that, and they will. They will convince a jury that you were partly at fault for the crash when the other guy ran the red light because you were less able to avoid it, and they will be right. Stick with what the engineers designed for the best braking and handling.

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Saturday, July 27th, 2013 AT 8:08 PM

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