Ive just started an experiment, diety level, lots of AI. Go nearly 100% science and get Alphabet, writing, litrature. Set up core and quickly put aside second city onto FP for pre-build GL. Once you hit litrature set science research to 0% and start collecting cash(or get iron working if you dont already and need spearmen for defence). The AI will be ahead on tec for a while but dont worry, if youve pre-built the GL from the start then it should arrive soon after you get litrature. Next thing you have the GL and jump up the tec tree to where the computer is, (compleating final few AT techs). With GL you will be ensured 3rd place in tec till advent of education. So with a lot of computers you should be able to sell your tec to lots of people. Sit at 0% science level getting all your science from GL and selling to other AI for a bit of extra pocket money.
This will give you lots of god in cash stored up (save it). This gives a couple of thousand years of free tec where you can focus all yor attention on expansion/war etc (more land and cities for later tec generation). GL becomes obsolete fairly at education(after getting 25 free tec from it), so start building librarys at the start of the middle ages, and so youll be ready for 100% science power after education. Then you'll have lots and lots of cash when GL becomes obsolete so buy tec from 1st and 2nd place so you become 1st in tec race, Now is the time to get the ahead, you can run a deficit for a long time because of the huge cash stockpile, and with increased territory and 100% science rate (you cant go under 4turns/tec so don't do 100% if you can get 4turn/tec at lower rates) it should be able to get ahead of the AI.