I am thingking about putting nose cones on my 1992 38 fever with bravo 1 stock drive 1st is there any advantage of doing this beings I only run about 65 mph and are there any disadvantage to doing this. Thanks for your help. Eric

No personal experience, but I've read many reports about nose cones being useless at best, and negatively affecting the performance at worst, unless the boat a) is already fast, to start with (well above 80s) and b) has an aggressive X dimension (which I don't think your '92 with stock Bravos has).
Probably someone will be be able to comment more specifically on your setup.

Eric, I'd probably look into 2" shorty lowers. Not sure how deep your propshafts are now. When mine was new and rigged with TRS, I believe the propshafts were around 5" below the bottom. Now, with SSM IV drives, shafts 1.5" below the bottom. 84mph gps with 625HP engines.

I would think you'd pick up some nice speed with 2" shorties and the right props. Maybe enough to get you over 70mph.