Gear vendor's with 3:54 rear gears and th400?

[chewychevy67]

I am tossing around the thought of adding a gear vendor's Overdrive in my 67 build. I had a 700r4 in my last truck and more important than any fuel I might have saved I sure loved how quiet it was. The drivetrain is all stock 327 turbo 400 with a Dana rear with 3:54 rear gears. 700r4 is absolutely not an option on this build. I know this set up would be better with 3:73 gears but I have my diff all done and buttoned up with new parts and really don't want to change guts. Any input from others who may have done or have this set up or is knowledgeable about this kind of stuff would be great. Just don't want my truck to be sluggish because I added this with the lower gears. Thanks in advance, Rod.