I am building a 408 stroker to put in a truck for towing and want to go supercharged. Is a m122 big enough for a 408 stroker keeping the blower below 18k rpms? I do not have 9k for a Harrop kit and used LSA blowers are 3k+ without a lid and I have a m122. How many ft/tq will it make?

 

If you really just want to tow with it, then sure it will be ok. If you want to make the sort of power that most people expect from a blown 408, then don't bother with the m122.