Question on fitment, please. The cruise-o-matic in my '66 F100 short bed 2wd 390 needs rebuilt. I have a core C6 out of a 1960s car FE block that I was thinking of having rebuilt and using that instead. I measured the C6 front to crossmember at 22.5" and front to tail end at 34". My cruise-o-matic is shorter at around 20.5" to crossmember and overall around 25". It looks like I have enough room on the rails to slide the crossmember back. I know nothing about C6 trans swaps. Will this trans fit ok in my short bed? I know the driveshaft will need shortened if I can get it to fit.

Thanks- Tom

 

Tranny will work, you will need to get a truck shift arm as it runs along the drip pan -- the car arm is kinda like this \ but not that drastic. You will want a different column and a drive shaft shop can adjust the ds length. Might be a good time to upgrade to power disc brakes and power steering, getting those needed parts from a donor.


John

 

This is a picture of my engine and C6 sitting in the frame. This truck came with a 460 and a C6 so there were extra holes in the frame already so I didn't have to drill any holes. The problem is the center cross member. You will have to remove it, "not easy with the cab on the frame" and make it into a two piece assembly. This was already done to this truck. Thank goodness!! That C6 is a little too big to get passed that thing.

 

Your comment about the cross member. Did 66's with AT have a removable cross member or in your case, some one may have removed the rivets and bolted it back in? I'm planning on putting in a later MT with integral bell housing and am pretty sure it won't go in unless I mod the cross member. Your comments would be appreciated. Thanks

 

In my case it was by the PO. This truck originally had a 3 speed overdrive. The PO took that out and replaced it with a C6 back in the 1980's. And modified the cross member. I think the smaller automatics FMX, C4 etc. will fit without removing the cross member. Not sure about that though.

 

This is the cross member that came out of my truck. There are probably 10 different ways to do this. But it does need to be strong enough to keep the frame from flexing since the radius arms and the cab mounts bolt to the same spot.

 

Thanks, John.

Crop Duster

I was talking about moving the rear trans mount cross member back, not the riveted structural cross member. If that is required I'll just have the COM rebuilt and forget the C6. My trans shop didn't think there would be an issue with fitment in that regard.

Tom

 

Tom, The rear cross member is easily relocatable, unbolt it, adjust it, drill new frame holes if needed, reattach. Trucks with riveted cross members came with manual transmissions as mine did. I front loaded the C6 attached to the engine. Shortly had transmission issues and the rivets had to be cut to remove the C6 from the rear, then the cross member was bolted back in.


John

 

Thanks, John.

My rear trans mount crossmember has a bolt each side, so I'm good.

Tom

 

There is also this version of the C-6. Its a direct bolt in. No need for messing with driveshafts.

If you were close I have a couple spares . .

I just took this one out of the F250 Ranger I am dropping the EcoBoost in.

 

Add my thanks to John and Crop Duster.

John, a question, did you remove your cross member in one piece or did it require cutting in half as per Crop Duster's picture?

 

Thanks Randy. I sent you an email.

Tom

 

Not cut, not sure why the one in the photo was cut. It is removed to allow the bell to pass through rearward. Should not need cutting.


John

 

Thanks John, sure does help knowing what you're up against.