you did post on here about this ? a 396/402 can be built to run i know i can . made a long post on this hit the wrong button . your not going to find a alum head made in the usa for 900. aset not going to happen . you need to watch the head size . the 396 will somewhat will want more RPM the block and most gm lower end parts can take way more then 500 hp is like falling off a stump . the 396 is more weight but a stronger engine then a 400 sbc . 454 still can be had i have a shop full of them coast of cores for good block s has gone up some the cost of building the 396 is going to be about the same as a 454 that why many have not used the smaller bore engine