Thank's for all the help---finally tracked it down. The part is about 4" long and screws into the trans. and the speedo cable screws into it, sort of an extension with a wire connection. Bought the car from the second owner in 96---he owned since 74. This part was partof a Cal. early polution...
I'll try to get some pictures posted tomorrow. It's gunmetal grey metallic, black top with white interior. Had the dash and door panels done by just dashes and the gauges redone by redline. Just got it back from the body shop couple of months ago. No rust---spent it's whole life in Cal. and Az.
Thank's for the welcome----it's really hard to track down this parts purpose. Got the shop manual and can't locate it anywhere. I think the problem is that the Challenger is a California car and they and some really weird polution addons.
Hi, We just joined the forum. We have a 71 challenger convertible we have been working on for quite some time. Finally got our 472 Hemi put in last weekend. The car was originally a 318 car. We have a question on part # 3438494 which is called a sensor speedo or an A/T NOX speed switch...