200-R4 question

I am restifying a 1970 Z28 and recently picked up a 200-4R transmission. Is there any modifications needed to have it work properly. I have noticed a
small 2 prong plug in on one side and want to know what it connects to. Will my original speedometer work with this tranny or will I need some sort of modification. Any info will be greatly appreciated Thankyou
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.