Slant 6 to 340 Engine Swap in 69' Dart

You know that the biggest tires you can fit in the back of a 69Dart are probably 255s right?
A regular hi-compression 360 will annihilate those. With 3.55s, and in Second gear at 45 to 50mph she will light those up with nothing more than a footstomp, and they will keep on spinning till I shift. My 367 with a 223/230/110 cam would spin 275s sometimes to over 85 mph.
I do not see the advantage of having a 416 in a streeter....... but I've never had one, either.
I mean why would I? the speed limit everywhere in Manitoba where I live, is 65mph on two-lane hiways, and speeding tickets carry huge fines. The cops can even impound my car, and/or take away my driving privileges. For me to have a 416 under the hood, for the one day in seven years when I maybe might go to a track three hours away, makes no sense for my situation.

For a streeter, traction is the #1 problem. And the correct rear gear is the Second. Any of the 318 to 360 SBMs can be engineered to haul the mail to 65mph, in a 69Dart with stock factory tubs.
If you tub it, and install 325s (or more), now you have more or less turned your 416-equipped car into a point and shoot type of car. To get it to handle will take several more thousands of dollars.
You know this right?
The 69-340Swinger with rally Suspension was a well-rounded pkg. Make it a 360HO with a modest cam so you can run 2.94/3.23s on the hiway, and it's done. Just a lil stall would be icing on the cake.