depends....
unless you cracked your timing chain cover you should just need a new oil pump. You can purchase an oil pump at most auto parts stores, but if you want a high volume or high pressure unit i suggest summitracing.com or jeggs.com. They carry many high performance parts.
Just being under an sc xr7 a few weeks ago(jesse) it looks as though you will have to raise the motor off the mounts a few inches to clear the oil pan out of the way. This is to gain acess to the oil pump itself and make sure you properly clean and replace the oil pickup screen so you don't suck up any big chunks of goo from the oil pan. It is a relatively straight foreward job just make sure to prime the oil pump via the ditributer shaft using the correct priming tool and a cordless drill or you will have a dry start and may damage the oil pump.
LAter
Dwayne