340 in early abody

lo23 yes thats what i had in it behind the 273 than the 318 , now going 340 6pxk . it will not handle this motor . so i'm looking at a multi disc setup , these cars are tight through the frame rails . i need all the room i can get . and the 10'' double disc clutch should be able to get it done . after all they make a 10'' double disc for mustangs gt's .