Is `#!/bin/sh' configurable?

Hi.

On some systems /bin/sh is not Burne Shell, e.g. /bin/sh is tcsh, but
there is /bin/sh5. It is looks like there is already knowledge about it in
the system: Makefile.ultrix4 has `SHELL=/bin/sh5' in it, but configure
thinks something else: config.status has `s%@SHELL@%/bin/sh%g'. (This is
really unrelated, because `src/bin/initdb/initdb.sh' has `#! /bin/sh'
hardcoded in it)

The result of the mess is that scripts like initdb are installed with
`#!/bin/sh', but they has function definition and tcsh complain about
usage of '('. 

BTW: After hand substitution I reach the point of 
IpcSemaphoreCreate: semget(key=4, num=17, 03600) failed: No space left on
device
The problem is that I have no idea how to enlarge the parameters on
`ULTRIX black 4.3 1 RISC', and it is looks like PG has no FAQ for
it. Anybody knows how to do it?

Regards,
ASK