If you dont have smog where you are and I dont think you do if the EGR tube has been cut and folded closed, and you having a feed back system and maybe needed a carb that you do a search for "feed back delete".
The feed back uses a computer to adjust the carb & timing and IF ANY of the feed back system is not working or missing the computer goes into "limp home mode" and locks the timing and the carb at full rich.
To bypass this system you need to install a pre-feed back carb (that may already been done?) and a dist. with vacuum advance and the wiring harness for the dist. and the computer could then be removed.
Again do a search for it so you can read up on it.
I think you started a post on the carb then removed it.
Just fill that first post back in with a picture of the carb & dist. so we can make sure of what you are working with.
Dave ----