I'm having problems finding the right vacuum modulator for a 68 firebird convertible with th400 transmission. In the pic below, mine has an extra leg to it. Found one on fleabay for $225 plus shipping but doesn't give the part number. Does the other style still work fine? Seems like it's probably the same thing just the og has the port on the side where the new has it on the end. But not positive

You should be fine with that modulator. If you get the red stripe one there is a screw you can adjust the shift point under hard acceleration.

This one has that screw also. Thanks for the response