I have a 351W at the mechanics right now. I'm putting aluminum heads on and the guy said with a "baby" thumpr cam from comp I should get a little over 400 hp. I was wondering if the cam would put a good sound out( Flowmaster 40s) and have some performance as well????

 

Do not see how it could hurt honestly... More air and fuel via duration will help power, but as the name suggests, expect some thumping at a low, slightly rough, idle.
I know kids like me think it sounds cool.
What brand aluminum heads did you go with? Keep me updated, I am planning a 351w swap... 1st goal running, 2nd goal power adders (already recently bored over with a mild cam)
Do not forget about exhaust headers if you want to get that awesome sound...

 

I always advocate going directly to the cam manufacturer and putting in whatever they recommend for my engine and needs, they know a whole lot more about what will be best than the average enthusiast no matter how well intentioned their advice! The manufacturer depends on customers being satisfied with their product, that's why they have a customer service support rep.

 

I will and thanks guys!