67-69 Dart swap questions

Unless you get a smoking deal on the 6.1, you can get stock 6.1 power out of a 5.7 for considerably less money though trading the cam & heads which are both easily handled as bolt-ons. The later a-body v8 k-member is preferable by many especially if you are planning on using the TTI motor mounts. In fact, I think it is required for TTI mounts

You should be able to use the stock 5.7/6.1 flex plate but remove the ring from it.

If you want to consider boost, I strongly encourage all of our customers to build a motor that is up to it. The stock blocks are not up to more than about 8 lbs. Some have gone well beyond that but usually kill the motor after only a few runs. I suggest to those who want to build up their motor as they can afford it to start w/ a forged bottom end and a NA cam. We occasionally offer a cam swap program for our customers who progressively upgrade their builds using our products such as now adding heads and a blower. Trade in that Inertia NA cam for an Inertia blower cam. When you go from the NA cam, many take that opportunity to go to some heads that are ready for it.

As part of the 10/30 cuda project, we are working on a stand alone system the would activate the MDS systems on pre-08 Hemis, including adding this feature to the 6.1 blocks :) Imagine running on only 4 cylinders conserving gas when loads are light and at the flip of the switch or automatically kick into the v8 mode whenever you want.

As for 1/4 ET's....try using one of the online ET calculators http://robrobinette.com/et.htm . Using 380 wheel horsepower and ~3300 lbs for the loaded car. ~380 hp is achievable w/ strictly a cam swap on the block and heads stock 5.7 . That shows a 12.19, ( in a perfect world) Either way that is solidly into the 12's. All you did was put a cam in, so you have barely scratched the surface as far as making some hp.