im interested in getting a new transmission for my 67 camaro, it has a small block 350 with a bds suercharger on it. its a b and m turbo 400 http://www.summitracing.com/parts/BMM-112002/ it says nothing about the horsepower rating, so i was wondering if anyone knew what its hp rating was and if it could take about 480+ hp

 

In stock form, the TH400 is rated to handle at least 450 h.p./torque. Back in the late 60's/early 70's, Chevy was putting them behind the 435 h.p. BB 427 and 450 h.p. 454 Vette engines (among other cars as well) without fail.
That B&M unit you show has better clutch plates, but in the h.p. range you want to go, the sprag can be the weak link in that trans. I would call B&M and ask them what they rate it at, especially since they don't say anything about upgrading some important components. That one reads like it's a little better than a stock rebuild, and probably is. Given that, you'll want to bump up at least to the next stage. If B&M doesn't offer a stronger one, try other places such as here (which I'd trust more than B&M anyway): http://www.tciauto.com/Products/TC-%27GMTH400%27-0.aspx
Or maybe find an independent builder who has a good reputation, ask around your area.

 

I would look into 4 speed auto like 4L60 or 4L80 with lock up converter for street use

 

i think the th400 is capable but you might have to put a better kit in it but they can handle alot of hp