300-390 swap
New User
Joined: Jun 2017
Posts: 7
Likes: 0
As I understand it the 390 and the 300 have different bolt patterns on the back to the bell housing. The 300 is in the i believe "Y" block family of motors and the 390 is not. would probably take a tranny swap to boot and motor mounts are not going to be compatible. Other motor that would drop ridght in are 302 351 and I think 460, but not 360/390 blocks.
FTE Legend
Joined: Jul 2010
Posts: 32,875
Likes: 48
From: Northeast, OK
Jared - This thread is 15 years old. Also, the 300 has the small-block bell housing pattern, but you are right that the 302 and 351W would bolt to the tranny. Here are some thoughts about swaps, just FYI: Engine Swaps - ???Gary's Garagemahal.
4wd Low
Joined: Jul 2017
Posts: 14
Likes: 0
And why on Gods green planet would you ever want to ditch a running 300? It's one of the most dependable, torque monster, motors ever made. I had one in a '72 F100. I miss that truck. And that motor. You could stand on the ground inside the hood and work on it.
Fleet Mechanic
Joined: Oct 2010
Posts: 1,690
Likes: 32
From: Delhi, Iowa
Ive actually swapped a 390 into an 81 F250 before. the crossmember under the oil pan needed to be modified. I learned that AFTER the crossmember ate a hole through the first oil pan.
I did it like 15 years ago, maybe i was the one who made this post, under a username i long ago forgot.... who knows....
I did it like 15 years ago, maybe i was the one who made this post, under a username i long ago forgot.... who knows....
