I found this thread.....
http://www.montecarloss.com/community/ubbthreads.php?ubb=showflat&Number=778875
The guy in that thread is trying to swap in a 350 where his 4.3 had been. He takes some pictures (one from each side) showing how far off the motor mounts are. The good thing is both pictures show the 4.3 frame mounts in place. I hope this helps....
http://www.montecarloss.com/community/ubbthreads.php?ubb=showflat&Number=778875
The guy in that thread is trying to swap in a 350 where his 4.3 had been. He takes some pictures (one from each side) showing how far off the motor mounts are. The good thing is both pictures show the 4.3 frame mounts in place. I hope this helps....