Need help!!!

Okay. This is driving me insane. I have engine supports (towers) that I am trying to use to mount a 300 inline into a 1979 f250 4wd. The mounts that were in the truck when I got it bolted up great, but I was told they were for a 351/400 and when I measured the distance from where they would bolt to the motor from the transmission they were like 5” too far back.

So after a ridiculous amount of shaky research I was confident that fe mounts (300/360/390) from earlier 70s would work although I was told I may have to redrill one hole. Well after showing some pictures to some “experienced” builders I was told that’s what I have.

Well I did everything but flip the truck on its top and still could not get the mounts to line up to any more than 1 single hole! I was then told that maybe the mounts were different between f150’s and 250’s and that’s what I should look for.

So $300 later I have the new to me f250 mounts in hand only to find out they are EXACTLY the same as the ones I already have.

Could someone please tell me what I’m doing wrong. I’ve got to get past this point. I’m including 3 pictures. The first is a frame pic of the passenger side. The next two pics are the short and long support both held against the passenger side rail.

With as much detail as you can muster (crayon pics are great by me) can someone tell me how these get installed or if I even have the correct mounts for what I want to do. Thanks.