a cheaper alternative might be to get a 4.15" cast stroker crank.
kb-silvolte.com shows the #1271 piston (for a 383) as a 1.848" comp height.
1.848+6.76+(4.15/2)= 10.683", or .042" in the hole based on the blueprint height of 10.725" for an RB block.
based on my calculations assuming a .040" head gasket and 88cc heads, you're looking at about 9.96:1 compression
use a largish cam or a wide LSA to make the intake closing point late to bleed cyl pressure, and it should run on pump premium.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
| 
