I believe the partial oil pan gasket (repair gasket) is made a little longer than how much the oil pan extends past the front of the block. They require custom trimming to fit what you need so the front bolt holes line up.

Yes you can use RTV sealer in place of the gasket if you like. Just be careful not to draw the oil pan full tight up against the bottom of the timing chain cover as this will bend the front of the oil pan rail, let the RTV fill the gap.

Also the timing cover gaskets are usually made a little long and require trimming to be flush with the oil pan rail on the block.

Hope this helps