i built a car just like that one about 6 years ago, even a full cage in that sucker. power to weight ratio was a little to much. the car was a uncontrollable rocket.
Actually, small block and buick v6 conversions on old z-cars were pretty common; they were called Scarabs, named for the company that first sold the conversion kits (headers, motor/transmission mounts, replacment x-member, etc).
ooohhh those memories .... had a small block in a a/h mrkIII and a 240 for a short time ,,, sold em after a friend had to be pryed out of his big block 510