Head pipe for 62 lancer?

Your 62 has that inline trans filter making it a bit tight down there.
Pull the trans pan and change the filter screen to a 64 filter with 2 pick up holes one for the front pump and the other for the rear pump. Yes up until 65 you could push start a Torquflite. Now that you have the modern filter in the pan you can get rid of the inline filter and reroute the trans cooler line to get the clearance you need.

Chrysler wanted the slant 6 to have a lot of low rpm power so the header outlet was 2 1/4" the head pipe 1 3/4" all the way to the muffler and 1 1/2" out the tail pipe. This gave it a lot of back Pressure and increased the low end torque . But at the expense of high rpm passing.

My 66 has power steering and 904 auto with 2.90 rear gears . I took it to the muffler shop and had them make a 2 1/4" head pipe and exhaust system . They used a muffler that gave it just a bit of back pressure. It really woke the car up on the freeway almost like a V8 .

We did a later Duster without any back pressure and it fell on its face, so we changed the muffler to give it a bit of BP and it woke up.