Motor mounts 440

[Jeff72clone]

Anyone know the size of the 440 motor mount bolts?
I’m adding BFS coil over suspension to my 72 B b body. Have 440 sans motor mounts.
Looks like 1/2 inch bolts too tight. 7/16 loosey goosey. I think top bolt 4.5-5 inch long and bottom only needs 1-1/2 to 2 inch bolt.

 

[Vaanth]

Anyone know the size of the 440 motor mount bolts?
I’m adding BFS coil over suspension to my 72 B b body. Have 440 sans motor mounts.
Looks like 1/2 inch bolts too tight. 7/16 loosey goosey. I think top bolt 4.5-5 inch long and bottom only needs 1-1/2 to 2 inch bolt.

View attachment 40157

The engine bracket bolt/washer/nut is the same for the 440 as other Chrysler big block wedge engines. Engines through 1973 that used the separate bracket and insulator used one style, and 1973 - 1978 engines with spool mounts that integrated the bracket and insulator in an insert used a different style.

The bracket/insulator style mount uses bolts/washer/nuts as follows:

• Bolts and nuts are 7/16"-20 thread.
• Bolts and nuts are 5/8" hex, although some 11/16" hex nuts might be found.
• Nuts are center lock style.
• Bolt lengths are:
  • Two 2"
  • Three 1.5"
  • One 4.5"
  • NOTE: Truck and some early cars did not use the long 4.5" bolt used with the tube style bracket (for dipstick mount). In this case, an additional 1.5" bolt is used.
• Washers are thin steel, ~11/16" - 3/4" outer diameter. The washers are placed against the block areas.

The following images shows the bracket/insulator mount style bolts/washers/nuts:

The spool style mount uses bolts/washer/nuts as follows:

• Bolts and nuts are 7/16"-14 thread.
• Bolts are 5/8" hex, with captive washers.
• Nuts are 11/16" hex, flanged, and a prevailing torque lock style.
• Bolt lengths are:
  • Five 1.625"
  • One 1.5"
  • NOTE: In some cases, a second 1.5" bolt might be substituted for a 1.625" bolt.

The following image shows the spool mount style bolts/nuts:


The two bolt/washer/nut types can be interchanged between the bracket or spool type mounts, except for the long 4.5" bolt.

NOTE: Some variance may be found over the years depending on the time and assembly, but sizing/style is generally as described.

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[Jeff72clone]

Thank you