It is not easy to get a naturally aspirated Series II (L36) into the 14'*, especially in a Bonneville. The fastest N/A GT Grand Prix is 13.80 and he has higher compression (10.something), bigger heads, a BIG cam, very good intake, very good exhaust (headers and all), 3.69 gearing (as opposed to stock 3.29), obviously a reprogrammed computer, a lot of added timing, and he runs slicks and the hole works, I think they have something like 15 grand invested in it. The second fastest is like a 14.4 and 3rd is 14.5. These people have a lot done to their car also, and they are GP'* so they are smaller, lighter, and better set up for straight line acceleration. Unless you have a lot of extra money, my recommendation is not to try. I would say get a CSC and you will be all set. They are like $4000 but they give like a 150 horsepower gain, and that my friend adds up to 355hp, which should definately get you in the 14'* if not 13'*.
Making it so you can take out your headlight for a ram air effect will definately help (it generally gains about 1 tenth of a second in the 1/4 in GP'*), but you will have to do much more. Probably a full exhaust, headers all the way back. All the normal stuff like T-Stat and plugs and such. Although I hate nitrous, to get into the 14'* for a reasonable price, that is the only way to go, but I would never use the stuff.
1990 Maroon Grand Prix STE McLaren 3.1 Intercooled Turbo, 14.695 @ 94.49 on 12psi before cam/heads/etc.
1990 Bright Red Grand Prix McLaren 3.1 Intercooled Turbo, 14.819 @ 92.72, 189whp
1999 Grand Prix GT 9.75:1|K&N|160 tstat|No Ubend/Cat/Res|UD Pulleys|Ported M90/TB/Heads|XPZ|2.55"|Pacesetters|Stage 2 I/C. 12.442 @ 112.78
2000 Blue Bonneville SSEi Supercharged Gutted Airbox|K&N|3.4"|1.9'*|WP Pulley|Custom DHP|180*stat|41932'*|No Cat. 14.681 @ 94.80
2002 Dark Cherry Grand Prix GTP Supercharged & Intercooled
12.084 @ 114.38 w/1.743 60', 315.6whp, Fastest Stock Cam M90 GTP!
NOW XP CAMMED, 340.6whp with XP, stock heads, Gen 3 M90, 11.984 @ 115.84 w/1.750 60'!
Most HP Stock Heads Gen 3 M90 GTP!
2004 Red Monte SS Supercharged K&N|3.4 Pulley|1.9'*|180*stat|41919 plugs|3" dp|No cat/ubend|DHP|Shift Kit. 14.2 @ 98
GOT BOOST??? Friends dont let friends drive stock!