Tunnel Ram, stock specs??? That dosen't mix. To make an engine run properly, it needs to be able to pull a negative preassure ( Vacume ) and, a tunnel ram almost never allows that due to the larger amount of volume space ( EX. the plenum on a Edle performer will pull vacume faster due to the small space in the plenum, a tunnel ram, has a large space so, more volume ), you can fix and ajust things to help it but ither way, the tunnel ram will make power at the high end of the rpm scale, prolly start at 4k and end at 85-9k if you feel safe with those revs ( 327 should pull 8,500 at least ). Your best bet is to forget the tunnel ram and , if you want power, get a 6-71 blower, because by the time you tweak the engine to work with the tunnel ram, you would be able to mount a blower to the 327, as your 327 probably arleady has 8:1 which is optimal for a blown situation granit, there are tweaks you need to make to the engine to work with the blower like gaskets, and special carbs but, it will function better in a better rpm range, than a tunnel ram, without too much hassle.