99 Venture Timing chain replacement

I have my venture ripped apart for a antifreeze leak. Turns out to be
the combonation timing gear/water pump cover on the passenger side on
the van. Anyway, bought all the gaskets, parts etc. I am just
wondering if there is a half of an oil pan gasket they make for this
job. I am not dropping the whole oil pan, but the timing chain cover
meets up with the oil pan. Do I need to buy a whole oil pan gasket
and trim it, or do I just put some rtv on it? The gasket is in tact,
so let me know what you guys think.

thanks

Leon