451 Combo under a stock 1969 Dart Hood

What k frame & mounts are you using? The B lock is a short deck engine compared to the RB engine. They installed 383's in Formula S Barracuda's & GTS Darts without problems. It also depends on what intake you decide to run on your application. That's just a start, we need more information about the project.

I was thinking RPM Air Gap. I was going to go with Schumacher Mounts but that does not seem to be an option. So maybe now a Gerst Suspension. I was wondering more of fitment with the RPM Air Gap intake.