what is this car?

I think the baddest motor you could get in a Lotus Seven was around 100-125hp, and even that was seriously quick. Can you imagine a 350hp Honda, Mitsubishi or Subie in one? Yikes! ( probably equivalent to a 1300hp hellcat). I think Caterham will sell you a 1500 lb version with 250 hp.
The original Lotus 7 was just under 1,000 lbs. Problem with those is the frame cracked just behind the seats. Caterham worked for Lotus and bought the production rights when lotus decided to cease production. Caterham put braces and brackets in to strengthen the frames. Depending on the engine chosen, curb weight was up to 1,200# to 1,300#. They have one model called the 620R. The 620 refers to HP per ton. A fair handfull. That is in comparison to a new Challenger, Camaro or Mustang at 1,100HP, and any of those will have traction control and stability control, which the Caterham does not have. Caterham has a few models with more sedate drivetrains. One new one goes back to more like the original with a modern 3 cylinder engine. Still a responsive street performer.
Too bad the TD did not have a 289 installed as the hood sides would fit. The 289 is about 80# lighter than the 283, both all iron engines. 289/302 fit under Model T hoods easily while the SBC is a snug fit. 351W and 351C are taller and wider so do not fit well. I think the SBM is also taller than the SBC so would not fit well.
A guy in Edmonton, Alberta years ago installed a 340 into a Datsun 240Z. Those had a fair bit of engine room.