Will a GM 4L80-E Transmission line up with 283 engine in 1963 Chevy impala?
No, a GM 4L80-E transmission will not directly bolt up to a 1963 Chevy Impala's 283 engine. The 4L80-E is a much later design (introduced in the late 80s) and has a different bolt pattern and overall dimensions than the transmissions originally used behind the 283 (likely a Powerglide or a 3-speed manual/automatic). You would need an adapter plate and likely significant modifications to the transmission crossmember, driveshaft, and possibly the engine itself to make it work, and it's a complex undertaking.