4l60e swap questions

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by marine_enlisted, Jun 12, 2003.

  1. marine_enlisted

    marine_enlisted 1/2 ton status

    Sep 29, 2002
    Likes Received:
    Stafford, VA
    I am running a 5.7lVortec engine in my '86 GMC Pickup. Right now I am still running the 700r4 with a 208. I am planning on installing a 4l60e in the near future. This is due to the fact that on the Vortec throttle body the linkage is on the passenger side. I have the T.V. cable attached to the stud where the cruise cable should connect. It works ok, but I can't seem to get it to shift just right. It upshifts too soon, and if I move the cable one click , it shifts late and will hardly stay in overdrive. I think this is because the geometry of the throttle lever is different than the TBI or Carb. Also, I don't belive my convertor is locking up and I don't want to run it with a manual switch. Here is the big question; If I swap in the 241 from my '91 Suburban, will the VSS on the t-case tailshaft work with the Vortec VCM? The VSS from the 241 has 40 teeth so the pulse rate should work, and I will have to convert the speedo to electronic. When running in in 4-low will this cause the tranny to shift incorrectly? Another member said he used a reluctor wheel from Jags that run on the tailshaft on the tranny and drilled a hole in the t-case adapter in order to mount the VSS. I am sort of leaning toward the doing it that way and keeping the 208 with the mech. speedo, but I would like some input from some other wrench heads.
  2. dyeager535

    dyeager535 1 ton status Premium Member

    Dec 13, 2000
    Likes Received:
    Roy WA
    Well, I'm under the impression that it was still 2 pulse up until '91 or so.

    Are you running the Vortec setup know from a manual transmission truck now, so a change would have to be made to the computer with the tranny swap? I'm sure '96 would have been the higher pulse VSS, so a stock speedometer from one of these trucks (assuming 2 or perhaps even 4 pulse up until 1991) won't play nice with the 4L60E.

    Sound right?

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