I am looking to buy a first gen to built into a spec. racer. When shopping how do you know what model you are looking at (S, GS, GSL, GSL-SE, etc.)? Thanks for the help.

 

I'm not really able to help you, since the "S, GS" etc. model specs are USA only, but when you want to build it into a racecar there are not to many things that are important. All models are powered by the same 12A engine, exept the GSL-SE, that has a 13B. The 12A came in two versions, an early 79-80 one, and a 81-85. The difference is about 10hp, and lighter internals for the later one. The 13B is more powerfull, but I'm not sure if it'd be allowed in the race-class you want to enter.
If you decide on 12A: go for the absolute basemodel. Things like sunroof, powerwindows, aircondintion, it all just ads up weight.
So, when shopping: the least goodies is the one you want.
GSL-SE can be reconized by several things, but the most important is of course that engine: 13B fuel injected instead of 12A carby.

 

If you're wanting to do the race car thing, you want to get an S or a GS without the sunroof. Lighter is better. If you can, find a 4 port 13b (like I did) to put in there, you'd be even better off. My personal opinion is that the 6 ports have a bunch more weight and there's too much freaking electrical stuff to deal with. that's my two cents.