Is it possible to mount a Series 2 SC engine to a Series 2 NA Transmission? Or does GM use the same transmission for several different cars and it would be fine?

I dont think so; the SC has a 4T60-HD to handle the L67 power.

SE, SLE dont have he 4T60-HD

First of all i'm assumin that he is talking about his 97. Yes it'll work just fine. But the 97 has a 4t-65e.

Yes it'll take the power, but not anything heavily modded. 65'* seem to fail more then the older 60'*. If you want the best power option for you car, long term, get a 97-99 L67 with a 4t-65e HD tranny on it, and a PCM and wiring harness.

this site will help tons too......www.l67swap.com

In 1997 only the SSEi'* got the 65, everyone else got the 60. You could always run the tranny on the SC until it dies and then get a rebuilt HD.

How long would that take? Or is there some type of package I can buy to beef up the tranny to hold a SC engine?

Not quite right, Mike. The SSEi and SC'd SE/SSE got the 65-HD in 97, and the non-supercharged models got the 65.

The last year for the 60 series transmissions was 96.