Question about Transmission conversion

[mrnapolean1]

I have a 1987 R10 Pickup that has a 3 speed transmission in it (I don't know what variant it is) and 3rd is going out.

I have a 700 R4 overdrive transmission that came out of an 90 Silverado pickup (new body style).

I would like to put the 700 R4 in the 87 R10 pickup.
It looks like everything will slip into place but Im not for sure how the mechanically driven speedo is going to hook up.

the most important is the torque converter lockup (the 4 pin square plug) is going to work.

 

[marks86]

http://www.bowtieoverdrives.com/index.shtml

id call these guys

 

[yevgenievich]

if your current three speed has the connector , it should be the same. For speedometer, a 89-91 suburban speedometer swaps right in.

 

[mrnapolean1]

if your current three speed has the connector , it should be the same. For speedometer, a 89-91 suburban speedometer swaps right in.

My speedo has the cable. Its not the electronic type that they used in the 89-91 suburbans.

And I don't believe that my current Tranny has that connector considering its not an overdrive.

 

[yevgenievich]

some three speeds had lock up torque converter, which had the four pin connector. they were th350c instead of th350. There is a vacuum controlled lock up switch that can be installed with brake switch and the harness to go to the transmission if the truck already does not have it. Or manual tcc can be wired up. As for speedometer, 89-91 speedometer is electronic, and will work with a later electronic spedo 700r4. It is also a direct replacement for an earlier cluster

 

[Hoodbj]

Not to hijack but is the electronic speedometer able to be used in the older cluster or does the cluster need to be replaced also? I have a later model 700r and the speedometer for a backup in case mine goes out but wasn't sure.

 

[MadOgre]

You need to make sure the wires are in the correct spot on the connector.

You need the whole cluster to do the speedo swap and its not just plug and play. Its complicated enough that I have run with out a speedo for several years now.

 

[mrnapolean1]

You need to make sure the wires are in the correct spot on the connector.

You need the whole cluster to do the speedo swap and its not just plug and play. Its complicated enough that I have run with out a speedo for several years now.

no way to make/convert the transmission to run the speedo off the cable?

 

[MadOgre]

You can run the VSS off of a cable drive. not sure about the other way around

 

[mrnapolean1]

How hard would it be to install an electric speedometer that will work with the 700r4 I plan on installing and that will work with my existing cluster housing?

 

[bucket]

You can put the mechanical speedo parts on the 700r4. Just pull the parts from a donor junkyard trans, or maybe see if a local trans shop has them laying around.