If you are not matching numbers, the remanufactured ones are probably less than what you will pay for an 8338 core, and they should have some warranty. Call them to confirm fit and ask who rebuilt it. If concerned over heat, get a thermal wrap too. I've seen rebuilt 8338s go for near $300, and cores well over $100 on the usual eBay, etc. if you decide to take that approach.
I assume you have a PG and need an under pan/inspection cover. Some vendors list them as fitting SBC and BB, but my experience is many are unaware of the difference and what they sell is often for a 153-tooth flex plate. You need the one listed for a 62-70 BB/168-tooth. I got mine from Ecklers - their part number 166962. Compared to a repro 153 tooth pan, it's overpriced IMO, but you know it fits. Once an original pan is off the car, most don't know what it fits or the depth differences. You'd need to confirm a used one came off a big block car. Summit doesn't have a 168 cover, and JEGs has one listed as both 152 or 168 but bad reviews. Good luck.