The heads are designed to fit the M117 only.
You may want to consider selling the heads as if they are not damaged, They may fetch more from a collector in the USA then what your modified 450SLC would be worth.
The value of the heads is to one who is building a period vehicle that the heads were used on.
They are extremely rare.
A 450SLC never had the M117 DOHC engine option so even though it would be a great performing vehicle it would have diminished value, perhaps less then a pristine stock 450SLC
