The fact the steering box is right in the area needed for the core support cross member is well known and one of the challenges for this type of swap. That is one reason for the original radiator thread is to identify other options before I dive in and find/fab my own solution.

It is quite possible to recreate the crossmember and to shoehorn a radiator into the area. I have seen it done with the "desert cooler" radiator. Keeping the original core support is my current plan to maintain fender/cab references. If I need to modify it to make a rad fit then time will tell.

The website I referenced in my other posting gives some guidance towards this solution. Thanks for the comments.

As to your earlier comment on 78 GP steering components being unique I can find no info to back that up. Where did you get this information? Everyone I have discussed this with knows of no problems with any 78-84 series interchanges. A check of part numbers for various years does not identify any differences.