Try contacting maniac electric motors and see what they can do for you, I just dealt with one of there alts for a subaru and it was rated 160 on the low end and at idle we couldn't pull it down below 14.2 and I know we where pulling well over 160amps we had every item including the stereo going full tilt. I will say don't order the big 3 kit from them it's just cheap stiff 0g and china made ebay terminals and take a wire brush to the pulley and get all the **** paint off it BEFORE you start it for the first time!
electrical: Optima yellow top X 2 big 3 in monster OFC 1/0g high output alt by maniac electrics
HU: JVC AVX-77 touch screen
Front stage: RE XXX 6.5" comps
front stage amp: Rockford T600.2
subs: 1 Sundown ZV4 12"
sub amp: Rockford T2500.1BDCP
Enclosure: ported (by JayDubb757 )