87 V20 transfer case - what will replace?

[crosby]

I have an 87 V20, but it's a body on a 1977(ish) frame. The tranny, transfer case, axles are all from the late 70s. So, my truck has TBI, but no vehicle speed sensor on the transfer case to feed the computer. Anybody know what fits to replace this? What years would interchange, etc.? If I could find a rebuildable transfer case from a V30 or newer K30, that would fit, I'd like to use a 205. I also have to hook up the original (1987) exhaust manifolds so I can connect the oxygen sensor too. Apparently Edelbrock doesn't make the Tubular Exhaust System for an 87 V20 with cats, AIR tubes, and the oxygen sensor. I have a 350 I pulled out of an 87 Jimmy, which seemed to plug right in everywhere else. Thanks very much for your help guys!!

[u2slow]

'87 would still have originally used a cable-drive speedo at the t-case. The electronic signal for the ECM is derived at the gauge cluster via an optical encoder built into the speedometer.

Swapping a transfer case by itself can be a headache.... there are so many variations on splines, adapters, and transmission output shafts.

The o2 sensor can be installed into any exhaust system... just a matter of welding a threaded boss into the head pipe. This is often the factory method - not all TBI exhaust manifolds have a boss for the sensor.

[crosby]

hi, thanks for the info. So are you saying the 87 xfer case would be no different? (having an ouput connector of some type) If so, I am in good shape then. The transfer case I have does drive the speedo by cable (I believe). Hopefully that will work. I do have the manifolds off the Jimmy which do have the O2 sensor boss, just need to be cleaned up and need a new sensor. I wanted headers, but this is cheaper for now anyhow. I can worry about custom exhaust on the new frame. Thanks very much for your help!!

[u2slow]

Originally Posted by crosby

So are you saying the 87 xfer case would be no different? (having an ouput connector of some type) If so, I am in good shape then. The transfer case I have does drive the speedo by cable (I believe).

Correct, the mechanical cable-drive speedo was used thru 87 on pickups, 89 on K5/Burb, and 90 on crewcabs.

[crosby]

Thank you, that is good news. I have an older 205 I would like to rebuild if I ever can find a TH400 adapter for it. Have a good one!

[u2slow]

205 is strong t-case, no doubt.

Like I said before... so many variations can make for headaches. The GM 205 came with 4 different input shafts, and two different bolt patterns. Each is transmission-specific.

Many times its easier to source a complete trans/t-case combo, than to make mismatched components work together.

Can you identify the 205 you have on terms of spline count (10, 27, 32) or bolt pattern (6 or 8 bolt).

[crosby]

I have a 203 now, and don't want to spend time and money rebuilding that. I haven't looked at the 205 for a while, but I believe it is male 10 spline output. I want to convert it to a female 32 spline. I believe it's a six bolt case....