1970 Challenger R/T build sheet location
 

Where is the build sheet located if not under the rear seat. Also how do I tell if the motor is a number matching motor?

RE: 1970 Challenger R/T build sheet location
 

the VIN should be stamped on the engine block, and the rear of the drivers side of the engine. i believe that the trans can be identified by the number stamped on the drivers side as well, right above the pan.

RE: 1970 Challenger R/T build sheet location
 

If it's not under the rear seat, try the seat backs of the front seats. A few have been found in the dash over the glovebox, or under the carpets, but that's pretty rare. As far as VINs on engine & tranny, they are usually on pads on the passenger side of the components.... engines usually found about halfway back, just above the oil pan, and the trans just above the pan, towards the front on an automatic, and approximately half-way down, towards the front on a manual.

RE: 1970 Challenger R/T build sheet location
 

here is a few places to look. i just went through the same thing with mine. found one for a convertible and my car.
-Taped to the back side / top of the glove box insert.
-Under the front bucket seats in the springs
-Inside the bucket seat backs
-Under the rear seat bottom
-In the rear seat back.
-Under the package tray(speaker shelf)
-Under the carpet