Nos Direct Connection x block
The heads aren’t worth what they used to be since cheaper heads can be made to flow nearly what a W5 can. For a as cast W5 head loaded, I’d price them cheaper what a Trick Flow costs. Unless you have titanium valves in the head.
The wide covers were $300 if not more new. There not made anymore. So the price is more expensive. Pay the price if you want them.
Hedman race headers? IDK what they are new or available. You’ll need to check that. Otherwise, a good header is an easy $1,000.
The MoPar X block was somewhere around 3K. But this depends on the exact X block. There are many to choose from back in the day. You’ll need the part number to know exactly which one you have and find out what it was new. Since those also are t made anymore, the only comparable part is a Ritter block. Check out his prices.
Rocker arms can vary in price a good bit depending on who you go with. Harland Sharps are just under $1,300. TD or Jesel are more money and complicated systems but are much better. There really race material.