Son's 77 Lemans may need an engine LS swap maybe.

[Over2tonsoffun]

About a year ago. My youngest son picked up a 77 Pontiac Lemans That was an actual field find. Where it had sat for at least 20yrs. We have been slowly working on it trying to get the original Olds 350 Engine running. We have changed:
Fuel tank
Fuel pump
oil/filter change
plugs
Cap/rotor/plug wires.
cleaned the metal fuel lines/ replaced the rubber ones
rebuilt the carb.

We have been trying to get it running with no luck. I wasfirst thinking it was the timing as it may have the nylon timing gear teeth. Checking the timing mark was right at the mark on the balancer at TDC. Still no start.
Then I thought the carb as it didn't have any fuel in the bowl. So today I took a known working carb ( off my 71 Buick Wagon) an put it on. It still wouldn't start all it did was pop through the carb. I am thinking something is wrong in the engine.
I told my son he has 3 choices: 1) rebuild the original Olds Engine 2) Find/ rebuild and drop in an appropriate Pontiac engine. or 3) since it already has a corporate motor in it already drop in a LS 5.3.
With the LS where would be the best place to get the motor mounts, Etc for such a swap. What exhaust manifolds would be best in it. Headers would be out of his price range. It will be a while before he even decides. With some health problems getting worked out he is on leave of absence from his job. So no $$$ for play.

Sorry for the long post.

Tim