273 or 225?
The best way for you to determine what engine you really desire is to find a good Mopar guy that has said car and have him take you for a ride or let you drive it! Be it whatever. Then you know! I have had just about every A, B and E (and F body) body and combo there is from 62 up to 79, from slants to 426 hemis and all in between (170,225 273 318 340 360, 383, 426 wedge 426 MX, 426 hemi and 440) auto 4 speeds 3 speeds 4 speed OD. Most stock. a couple not so much. BUT I have never been a drag racer other than the rural 2 lane blacktop time trial decades ago. I could not see the cost of it all. Point is every engine has it good and not so good points as to power, little things that an be problems as far as breakage, or power or durability.
I measure my enjoyment in this hobby is by smiles per mile and smiles per $$$> What can I love and afford!??? If I can't love it, then why have it!???? IF I was wealthy it would only be by smiles..period!!!! But I am not!! I have loved both slants and and big block cars and both give a different feel and type of enjoyment, just hard to explain. I find joy in the art (beauty) and design of most all old cars. BUT.... I see NO art in many models these days although I look and try to see it!
I never knew what torque felt like till I was 14 and had a ride in a 62 or was it 63 409 4 speed Impala. Wow.! I had never been over maybe 60 till my parents bought a new 55 Pontiac and I was riding with mom driving it back from the dealer and she "opened it up'. I looked over at the speedometer and it was begged. I asked how fast were we going. She said about 60 ( I called bullchit in my mind!) and she let off. I was 7.