no it's not necessary. all u need is the caliber & twist rate under the hanguards, nothing more.
Moleman, you are a freakin' genius! This is exactly why these companies do this. I call them Pecker traks....
BTW. Vulcan is selling their Carbon Aramid lowers for $30.00 now. I have worked on several of these, and own one. Aside from having to slightly file the trigger hole, they have been perfect. But nobody will touch them because they say Vulcan on them. Thus the price point. This is the best deal going right now.
Here is the link:
Check it out.