I would say a NASCAR block would have to be an SVO. In short, it is worth more than a regular production block.
I would say don't do it.
This really belongs in the Blue Oval Lounge.
Moved to 
Blue Oval Lounge
------------------
SVO siamesed 351 stroked to 417ci,Yates heads, solid roller,Trans King glide and a little blue bottle 
of giggle gas.   
My Car