273 to 340 swap in 65 dart

I purchased a "kit" from Brewers that included (among other things) a resized Z bar and special throw-out arm that should deal with some of the issues of fitting a 340 bellhousing into my narrow A body. They didn't mention any clearance issues when I discussed my plan with them, but I'm sure there will be several unexpected clearance issues before it's all over. I'll be cutting out my hump anyway to install the fiberglass hump for the 4 speed.
I think I'm going with a gear vendors overdrive rather than the Keisler 5 speed. I've built several Triumph TR6s over the years and am very comfortable with Laycock de Normanville electricly activated overdrive they use. As a matter of fact I like the idea of using a TR6 column mounted switch to activate the o/d and using a chrome plated stalk mounted brhind the turn signal stalk like the TR6 uses. Volvos and some Triumphs and MGs used a switch on the shifter but that wouldn'y look right on a Hurst shifter to me. Anybody gone that rout with an early A body?

Jim