Php – Install PHP 5.1.2, Requires: libcurl.so.3()(64bit) error

I'm trying to install php 5.1.2 on a CentOS 6 server (for grandfathering in old websites).

I downloaded an RPM file ( php-5.1.2-5.x86_64.rpm ), but when I use:

yum install php-5.1.2-5.x86_64.rpm

I get the following error:

Error: Package: php-5.1.2-5.x86_64 (/php-5.1.2-5.x86_64)
Requires: libcurl.so.3()(64bit)

I have tried several things including the following:

ln -s /usr/lib64/libcurl.so.4 /usr/lib64/libcurl.so.3 (To make it symlink to the newer version)

Downloaded curl-7.15.5-2.1.el5_3.5.x86_64.rpm and took the libcurl.so.3 out of the rpm and placed it in /usr/lib64/libcurl.so.3 with the same permissions as libcurl.so.4.

Nothing has worked. Any ideas?