is there a manufaturer who make a 4 lug(porsche) to a 5 lug (gm) bolt pattern?

huh??

only way to put GM specific rims on a 914 is adapters or have your hubs redrilled..then you have to find rims that have the correct offset...not easy or cheap...personally I find it more cheesy than when I put 4x100 (Honda,Miata,VW GTi rims on my car)

Are you asking about the wheel adapters that always seem to fail?

i guess i am asking ,because i don't have your expeience!