If I am putting a '73 400 in a '69 bird, which type of engine mounts would I use? First gen or the later style?

A 1973 400 block either has the three holes for the newer style mounts or it has 5 holes so you can use the orginal 69 mounts. If the block has only three motor mount threaded holes you will have to use the conversion mounts that the aftermarket companies sell.
Jim

I believe that I have all of the holes. I guess I can use the first gen mounts. Thanks.

Todd

Todd,
A lot of the 73 blocks had the five holes. You are in luck, first gen mounts are inexpensive.
Jim