69' Dodge Dart Resto/Upgrade in NY

Let the journey begin...
Had this Slant 6 225 Dart with a/c for the last 23 years (and brought all 3 kids home from the hospital in it). Still has the fender tag and build sheet.
Picked up a 340 for it along the way and always promised myself I'd drop it in, so now's the time. I am not a great mechanic (learned everything I know from my Dad [who was a master] but he was not a good teacher) so I'm going to do the best I can and I'll use this thread as a diary for motivation and help.

It was originally a 3 speed manual car but previous owner changed it to auto on the column.
Was originally T5 bronze fire metallic but the guy painted it a Pontiac green.

Here's the 340. It's been sitting for 20 years and locked up. The guy I bought it from said it had been circle tracked and seized up. He said it had been bored .30 or .60 over already, not sure.
Am I correct to assume it is a 1972 block? I believe it is worth saving due to how rare 340's have become. If I have to sleeve the block I wonder how much that would cost?
I also want to keep the a/c when I drop the 340 in.

I am also converting from auto on the column to console on the floor. I have a console out of a 1968 Dart.
Also converting from bench seat to bucket seats. I have a pair of original Dart bucket seats.
I tore the carpet up today and it looks like there are no holes for the bucket seats.
Did they use different floor pans for buckets vs. bench?
Do the brackets on the bucket seats look original? Looks like they are missing studs (and the studs for the buckets looks much smaller than the ones on the bench).
What is the best way to install the bucket seats?
Thanks.

340 1.jpg

340 2.jpg

340 3.jpg

Console interior.jpg

front floor.jpg

Front seat bottom.jpg

Front seat side.jpg

interior shot.jpg