I have a 1986 pontiac firebird with a 6cyl multiport injection mated to a 5-speed transmission. I have a 350 built up pushing about 380 hp and I was planning on throwing it in the firebird. I was wondering if the 5-speed tranny would hold to that kind of power. I am planning on racing it, so its going to be beaten on.

In a simple answer, NO. Save yourself a lot of anguish and get a Richmond 5 speed if your going to beat the snot out of it.

Watching trannys blow chunks is fun!

dont even waste your time and money, automotive parts are engineered with low mechanical limits to keep mfg costs down, your current trans was not engineered for the the mechanical stresses that your want to throw at it

You'll grenade that thing for sure!