I don’t think it’s the coupler the guy I bought it from said it has made that smell since he owned it for 3 years. I thought initially it smelled like electrical so I changed the alternator and that didn’t change it. When I changed the alternator I did get it pretty tight but I guess idk what the proper belt tension actually is. Do you know what tension is recomended/how to gauge tension?

Wow I just realized that the tank on top of the motor is for closed cooling. I am an idiot and have never had a closed cooling motor. There is no coolant in it! I assume this is why it smells hot!?

You just ran your engine hard with NO cooling of the block...

Disregard it’s not empty. I pulled one of the lower hoses off of the heat exchanger and DexCool started running out. But it’s low because I don’t see any looking in through the cap. I knew that couldn’t be true or it would’ve cooked the motor. Also it never runs over 170 degrees. I will add some dexcool but I don’t think that’s my issue.

Is it a V-belt setup or serpentine? My alternator bracket used to flex when over 4700 rpm and start burning the belt.

Interesting, mine is a serpentine belt. I thought about going ahead and replacing it and seeing if it slipping was the issue. Did you have V-Belt or Serp?

Serpentine, has the same belt routing and brackets as the 7.4 MPI. Ended up shredding a belt eventually.

I would check the coupler regardless, this is what I found on my 252 with a 502. Not sure how it lasted?

I don't know if you've identified the problem yet but telling the techs here that you've got an un-described 'strange smell' is like going to the doctor and telling him that you've got 'bad feelings' .
Is it a metallic odor ? An electrical smell ? A burning smell ? Smell like burning paint or rubber or oil ?
It doesn't sound to me as though you overheated though as there was probably just enough coolant circulating to run ok and I'm presuming that no overheat alarms went off.

edit to add ...
I have a friend who had a strange engine noise from one of his 350 Mag mpi's that I located using my nose . An exhaust gasket had blown on one port and the slight odor of rotten eggs in the engine room gave it away .