Northstar Engines and System Technical Discussion Discussion, What's the difference between the STS and SLS engines? in Cadillac Engine Discussion; How did Cadillac get the extra 20hp out of the STS engine? Intake? Chip? Plus, who makes a good chip ...
Re: What's the difference between the STS and SLS engines?
Really it's the tune/PCM's. Only the intake cams are different on the newer N*'s. Personally I think the cams are better on the base models. The real noticeable difference comes from the different final drives, 3.11's on the base SLS, Deville, DHS, Eldo, vs. 3.71's on the STS, DTS, ETC. That's why I put those in my car, along with a bunch of other stuff.
Oh, and for your 95, which is OBD1 the only company I know of is FAST chips, I think, it is a pain in the ass for Cadies but I think you can actually find aftermarket chips for 93-95 N*'s. Good luck, do a search this has been covered before.