Got link?

If the file is on your server then there is no reason I can think of why yourdomain.tld/path_if_any/install/index.php won't run.

http://www.psychedelicjournal.com/
but the blog is under http://blog.psychedelicjournal.com/

I get a "403 Forbidden" for your home url http://www.psychedelicjournal.com/

¥

yeah, thats because the site is not up, wanted to get the blog up first and then take care of the rest

Just to narrow things down, can you create and upload the following 2 files to your home url folder

index.htm

<p>Hello world</p>

index.php

<?php echo 'foo = bar'; ?>

¥

Done
the links are

http://www.psychedelicjournal.com/index.php
http://www.psychedelicjournal.com/index.html

can you now upload the same two files to your blog subdomian?

also, compared to your home url folder, what folder does your blog subdomain live in? ie/ on most servers /some/path/domain_I_registered_with/public_html/sub_domain/

¥

Done, i uploaded the files to the blog subdomain too. thing is, i get the same 404 error now, but the index.php is there ....
the path is /blabla/users/myuser/blog.psychedelicjournal.com/

Is your blog folder chmod'd to 777? Just guessing... If so make it be what a folder would be if it wasn't 777. I think it'd be 755 but see other folders for a reference point.