engine swap

[mekobes44]

i want to swap out the 250 in my 83 c10 with a 350 also convert from manual to auto trans , how diffucult is this to do, i have the time my truck just sits in the driveway

[EricS76]

I'm about to do the same thing with a '77. From what people have told me, The motor and trans crossmember will work, but you'll have to move them on the frame. You'll need a radiator for a V-8 with bungs for the trans cooler lines. You'll need a auto column and all the linkages that go with it, or a auto shifter like lokar makes. Some have told me a 350 with a th350 will have the same driveshaft length as a 250 with the 3 speed. Some have said I will need a different driveshaft. That's as far as I've gotten, I'm waiting to pick up a dead 350/th350 from a friend. Maybe someone who has actually done this will chime in and help us both.

[red450ih]

I did the exact opposite. I pulled a 350/350TH from my '73 C10 and installed a 250/3spd on the column. Long story as to why, but this is also a farm truck so it just needed to run.

You just need to move the rubber engine mounts up one set of holes on both sides. Most engine towers I have seen have 6 and 8 stamped on them after you clean the grease off. When I put the 3spd in, I did Not have to move the trans crossmember at all, but I did have to change the front shaft (mine is 2 piece). You will want to get a V8 radiator and fan shroud as well. It's pretty much a bolt in affair. Not really any modifications that stand out in my memory.

Good luck,
Keith