how much horsepower can the 904 take?

a properly built 904 will easily handle the crate motor....

buy good kit with alto red disc...kolene steels...replace the single wound spring in the front clutch pac with a 24 spring kit.....use a 4.2 kickdown lever on the street.....also...get a TransGo TF-2 kit or buy a good valve body...

I currently have 3 904s in use for drag racing and they have several season on them with no problems... I am sure they are seeing more the 380 HP....