I have a 74 also,It has a flaming river box and milodon pan and you can view my butchery to get them to fit.I just going to use them to break-in the motor and then make some custom headers after that.
Here is a link to my (on hold) build,page 2 half way down.
Passenger side not to bad just one small ding. http://www.forabodiesonly.com/mopar/showthread.php?t=133981&page=2
With stock manual steering and no milodon pan the summits will probably work on yours...I do not know about the 4 speed.mine got a 727 in it.
Martin
