Speedometer gear help needed

[kp texan]

Yesterday, I had my gearing changed from the stock 2.73's to 3.73's and my speedometer is off quite a bit. Using the various gear ratio calculators on the internet, I figured (will be running 33's too) that I should be using a 42 tooth driven speedometer gear since the driving gear in my NP208 is an 18 tooth (Blue). The problem is that, in order for me to switch from the stock 35 tooth driven gear to a 42 tooth driven gear, I must change the driven gear housing (mine is only good for up to 39 teeth). I went to the dealer and they want $65 for the gear housing alone!!

My question is, which speedometer gear housings are interchangeable with the one used in the NP208? Is it the same gear housing that is used in 700R4 for 2 wheel drive trucks? I took it to one transmission place today and the guy said it looked closer to the housing used on the TH400 rather than a 700R4. I'd like to track this part down used rather than paying for a new one.

Thanks so much for the help,

Wes

 

[kp texan]

Well, after filtering through about 200 search results here on the forum I was able to figure out the part that I need. It appears to be GM P/N 1362293, which is a 40-45 tooth driven gear sleeve. After doing a little more research on the internet, it actually does look like the same part number that belongs to the TH400 transmission! I guess that transmission guy was right after all.