I have the opportunity to pick up a complete rolling chassis with a low mile 6.0L PS. How hard will this conversion be with a rolling, driving donor? Next question, I know the 6.0L is not a desirable motor... What are the exact issues?

 

FABRICATION FABRICATION FABRICATION.

It's called remove the bed and cab from your '75 and transplant it onto the rolling donor 6.0L powered chassis. All the work will be the fabricating needed to get it all to bolt up, and yet retain the appearance of your '75. Going this route I suspect will be simpler than trying to transplant the 6.0L into the '75 chassis.

 

Frame on the F-250 is bent. Would I need to keep the instrumentation for Diesel truck?

 

every single electrical part of the 6.0 will need to be put into hte 75, and you will also have to swap the rear axle into the frame to make the speedometer work.
then you will have to swap out the front suspension to support the weight of the diesel engine.
and you will have to strengthen the frame to handle the added power.

 

The instrumentation from the newer truck is needed? That kills it for me. Thank you for the input.

 

the new truck dash is electric. the old truck dash is mechanical