426 Wedge possible install challenges

Don't underestimate your crusty 273. You may already have a forged crank in there and a wonderful mechanical lifter set. If you put a good cam and piston set in there and the right 4 Barrel you would be down town Julie Brown. LOL
The unit that was in there was just a short block attached to the trans, no lifters or anything. Cam and cylinders/pistons had been exposed to the elements for many years it looked like and was covered in rust. It is now scrap metal at the recyclers and I am starting from scratch in the engine bay