M40 transmisson modulator part no. -Joe L

[Edward J.]

looking for part no for M40 trans. modulator, 3963820?

[William C.]

Re: M40 transmisson modulator part no. -Joe L

group 4.205, part number 8623983 as of the 4/83 parts book. Same 68-77

[Edward J.]

Re: M40 transmisson modulator part no. -Joe L

Bill, this part no.3963820 is listed on e-bay and was trying to see if its maybe an old part no. it says 68-77 corvette but with a 350thm trans. the part looks like its for a thm400 but maybe its not.

[Joe L.]

Re: M40 transmisson modulator part no. -Joe L

[quote=Edward Johnson (49497);432559]Bill, this part no.3963820 is listed on e-bay and was trying to see if its maybe an old part no. it says 68-77 corvette but with a 350


Edward-------


I'm out-of-town and away from my references, so I can't check this one out right now. GM #3963820 looks to be about a late 1969-issued Chevrolet Division part number, though.

[Joel A.]

Re: M40 transmisson modulator part no. -Joe L

The 350 and 400 trans use the same modulator. There are some calibration differences so they will work on different vehicles, such as Cadillac, or Corvette. Not sure if the part # is different on them, tho.

[Joe L.]

Re: M40 transmisson modulator part no. -Joe L

Bill, this part no.3963820 is listed on e-bay and was trying to see if its maybe an old part no. it says 68-77 corvette but with a 350thm trans. the part looks like its for a thm400 but maybe its not.

Bill-----


The GM #3963820 modulator was never used on a Corvette. It was used on 1969 taxi cabs with THM-350 transmissions.

The GM #3963812 modulator was used for 1969-72 Corvettes with THM-400. It was also used for most other Chevrolets of the period with THM-350 transmissions.

[Harmon C.]

Re: M40 transmisson modulator part no. -Joe L

I have noticed that most modulators sold today are a small gold unit not like the black large original found on 73-74 cars. If you are interested in configeration I would check out original cars for your model year to see what was used in the day.