Kjeld, I purchased my big block Pantera headers from Precision Proformance several years ago. At the time they still had several sets left. The bellhousing I use is from Quicktime, although I had to drill new trans mount holes 180 degrees from the GT40 pattern.
I was able to fit my engine in without moving the transmission rearward. There are several reasons to keep the transaxle in the "stock" location.
Let me know if you need more details concerning the engine swap. I am happy to share my experiences.
Matt
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