[chevy71super]

It looks like your truck is a 4 wheel drive so its probably in the right position. Its a common problem using an HEI. Mine was very tight, I had to cut a bolt off protruding from the firewall to get my HEI to work. the valve covers are also very close. If you move it forward you may need to mess with the drive shafts. An aftermarket distributor with a smaller cap should work fine. Doug