thinking about putting a nose cone on my heat,anyone have any experiences?good /bad?i think theres a hydromotive and an imco.im runnin a stock xr lower dont really wana spend the money on a whole housing

Chuck,
I don't know if they are still around, but the "Leading Edge" or LE was very similar in installed shape and dimensions to an IMCO SC housing. IMCO's looks similar.
Make sure you get somebody who knows what they are doing here to do the install. Any variation from perfect alignment and fairing can cause high speed blowout or other handling quirks.
Regards,
Steve

any idea whats the norm on mph gain on a heat steve?

There is no set rule Chuck, other than the faster you are currently running, the more they help. They are more hydrodynamically efficient (less drag), and they help keep your propeller "loaded" at high speeds, rather than deflecting water away from the propeller, like the blunt nose of a stock gearcase does.
80mph, not necessary; 85, will help some; over 90 will help a lot (3/4 mph, and better handling).......

i went from a bravo 1 to a teague platinum XR drive last year (XR upper case w/ IMCO lower) and noticed zero difference in handling or speed. my heat runs 80 all day long w/ a stock 28p bravo 1 prop and a high of 82 w/ a merc labbed bravo 30