A body dash frames

I have an A body rallye cluster and access to a ‘68 rallye cluster frame. I didn’t hear you say it won’t fit/work, but it sounds like i would need to purchase a rallye cluster harness. Is that correct?
If so, any idea of the cost involved for a rallye cluster harness?
TY
It will work you will have to weld up the key hole 67 to 69 key is in the dashframe70 up in steering column