Yes and no.
some domains I put a 302 some a 301 depends on how Google treats them.
Here's an example - I am subbing to a client that had over 200 sites - each had it's own domain name. I combined them into one - Most of the sites I put a 301 on some however I put a 302 on -
let's take this for example "club fortuna" that site had
no placement in Google - pretty good placement now under it's old domain name (it was placed inside a directory on another domain) - so I put a temp on it to see what Google would do - Placement - I'll leave it a 302 for a while ....lol -
http://www.google.com/search?hl=en&q=club+fortuna. If I see it nose dive, I'll do a 301.
Nothing is perminate with the engines - they come back......lol
Try it, if you see it doing ok leave it a 302 for a while - if it starts dropping change it to a 301.