I have a 1984 mercury cougar.
In 1990 I put a 1984 mustang engine 50 HO in.
The car ran great.
Now in 2004 I got a 1980 302 all rebuilt and done that was in a bronco and put it in the cougar and it runs great but has a vibation like flywheel!
Are they bal diffrent the the HO.
I used the my flywheel that came off the Ho
It has a c5 trans!! Woody