3SGE header on 5SFE?

hey,hopefully someone out there can help me with this, I own a 1991 toyota celica SX(GT-something in the US) its a 5SFE powered one and im 16, in australia, your not allowed to do any performance mods while on your learners plates, so im looking for some budget ways to get my baby going better without looking suspicious under the bonnet.
i heard somewhere(cant remember where)that ST160 series 3SGE headers will bolt on, and are slightly better than the stock 5SFE items?is this true?i also heard that the 3SGE head will bolt on and will provide quite a gain, minus the slight water gallery difference,which can be fixed.any help would be appreciated.

I do believe that Ive heard this to be true. But I cannot say for sure. What I can tell you though is that in my opinion is that for the power that you would get from doing this is not going to be worth doing in your current situation. I would wait until your able to modify your car and do this when your making other modifications. The reason I say this is that I don't think your going to get more than 10-20 more hp from this and this isn't just a one day job. I just recently had to remove my head on my 91 celica gt 5S-FE because my water pump went and my car overheated which caused one of my intake valves to get stuck open. It took one whole day morning to evening just to put it all back together. Taking it apart was the hard part that took a couple of weeks. I would recommend going down to an automotive store and picking up a repair manual so that you can see just what your getting into.

your probably right, i just wish i had more power! :( lol, yeh, i have a repair manual, and im an apprentice mechanic, ive done a few heads, i work for toyota, so ill just drag it into work if it need be done, altohugh, working for toyota, you would think i would know the answers to my own qestions wouldnt you? lol :P
but, at any rate, thanks for your help, i think ill take your advise, 10-20hp, is not worth it, no matter how desperate i am