Quote: Couple of things I ran into when putting an 87 318 in my 65 Cuda. The 273 exhaust manifolds hit the bump cast below the exhaust port for air injection, had to grind it off. The manifolds also do not fit easily. The exhaust port in the heads is almost bigger than sealing surface on the manifolds, careful positioning is needed there. Obviously you have the issue with the torque converter snout being smaller than the centering ring in the crank.
Quote: The easiest "right now" swap would be the LA 318. They have not been made new for quite a while, so it may take a while to find a used engine which is OK "as is". Also the smog era 318's are pretty feeble.
A Magnum 5.9/360 would be a nice big step up in power. Depending on how long you need to run it before the Gen III swap may be worth it... plus used engines should be more readily available. MA had a good series on "warming up" a 5.9 for car use.
Quote: I would jam an M-body 318 in it, 85-up 2bbl engine. Easiest possible swap to keep the car running and get a little extra performance. They are also really cheap.
I know a lot on the 273 won't bolt up to a 360. I was somewhat aware of the exhaust manifold issue and potentially an oil pan issue. At most I'd only keep a 318 or 360 in there for 2-3 years or so. If the 273 is able to survive long enough, I might as well just skip the small block step and go to a GEN III.
