Have hit the motor perch wall.
removed the 400 from the truck today
its a 79 f250 4x4 with 2 inch lift.
pulled the motor and trans as one. wasnt so bad but left ATF everywhere
then was looking at the diference in my blocks.
Both 400 and 390 are 15 inches from motor mount to motor mount
the 400 is 12 inches from motor mount to bellhousing.
the 390 is 14 1/2 inches.
Both c-6 trans are same distance from bellhousing to tranny mount.
this means the motor perches have to move 2 1/2 inches forward.
Only thing is my frame has a ridge right where the mount has to be moved to.
does any one have any input on this of what to do.
the 390 is from a 2wd so i cannot use the motor perches from it.
Have changed over the c-6's tailshaft, still looking for rear sump pan and pickup.

 

Grab some 300 straight 6 perches, they match the FE engines.

Josh

 

I've heard that perches from a 73-76 F250 4x4 that had 360s in them also would work to mount your 390.

 

Yah both those perches are rare to come by up at our junkyards.
Might just drill new holes in the frame. and will make her sit higher so there is more room for axle movement. will make a cowl out of fiberglass to fit it to.
Or buy a lincoln migpac 180 and mod the old ones.

 

try junkyarddog an see what they got. they can search all the junk yards in your state or across the country.

 

Modify the old ones, cut up some plate to make em work then if you don't have a welder take em to a machine shop.