Keep all original parts, Then build it the way you want it. Take a good look at Steve Lavante's SS( Monteman71) or Dan's '70 Z20 . Two fine examples , As nice as they come and built to have a lot of fun with. Definitely go with a hydraulic roller cam and never look back !!
Numbers matching ( this would effect the value the most), MINT condition, well optioned, I would have to believe the starting price would be around $35k
I would shop around . Here 40k would be a total ripoff of the customer.my Shafiroff 434 with 763hp was less expensive than that engine quote and came with a warranty. And you would still have another 24k to throw at it. SHOP AROUND !!!!