My glt has a 13g turbo in it, I thought it was supposed to be a 15g?

 

97 840? Is that a typo?

that is the correct turbo.

 

yeah typo, Which car came with the 15g and is it worth going to that or a 16t without a remap etc?

 

Either turbo will net you more gain. Your still limited with the engine management being stock. You can get a lot out of that 13 with engine management but really to do it right you need both. A 15G would be easier and cheaper to get but I dont think you would be happy with just replacing it. Higher boost pressure is where you want to go, your engine management is always going to turn you down so you should be looking at getting a tune if you plan on making some power.