#1  
Old 04-07-2021, 12:00 PM
roadhard roadhard is offline
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Default 400 tran. in 67 gto

67 gto , tran. leaks , only 56000 miles on it, took it to the guy who has done few for me, should i have him make it shift faster or leave it alone

  #2  
Old 04-07-2021, 12:21 PM
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geeteeohguy geeteeohguy is offline
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You can make it shift faster by a simple modulator adjustment with a pocket screwdriver. IMO, if you have the original GTO trans, it is programmed for that car, and I would leave it alone unless you are going to drag race the car. The factory '67 valving and calibration was optimal for the application then and still is now.

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  #3  
Old 04-07-2021, 12:35 PM
roadhard roadhard is offline
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yes i forgot about the mod. screw in for fast shifting

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Old 04-07-2021, 01:59 PM
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JSchmitz JSchmitz is offline
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Vacuum modulator adjustment affects part throttle shifts. Full throttle is controlled by the governor weights and springs.

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Old 04-09-2021, 09:33 AM
goatwgn goatwgn is offline
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A '67 GTO TH400 should shift fast already. When it is rebuilt, the modulator should be replaced with one of the small units with the red stripe on it, and be adjusted in for the quickest shift. Upgrade the clutch packs, and have a 4l80 roller sprag installed.

  #6  
Old 04-09-2021, 11:52 AM
roadhard roadhard is offline
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thank you , they also put in a new up date valve body, also had to put diff pan on

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