This is what Dart's tech sheet says. Although i've never measured a B/BLK, i do know the Little "M", which i've purchased 2 comes in .020/.025 taller= 9.020/9.025
Zip.
DART Iron Big Block - Technical Notes
Deck Height ................................................ 9.800" & 10.200"
Bore ................................................ 4.250" or 4.500" unfinished
Main Bearing Size ................................................ Standard BBC
Main Caps ................................................ All 4 bolt - Steel or Ductile Iron
Weight ................................................ 4.250" bore = 280lb / 4.500" = 260lb
Largest Recommended Bore .................................. 4.625"
Camshaft Diameter .................................. Standard BBC
Camshaft Position .................................. Standard BBC
Cylinder Wall Thickness, min. .................................. .300" @ 4.625" bore
Deck Thickness, min .................................. Adequate for all applications
Torque Specs - Main Caps 1 - 5 1/2" bolts 100 ft lbs
(with oil) 2 - 4 1/2" splayed 100 ft lbs
Dart’s inner head studs 3/8” – 7/16” stepped 50 ft lbs
Blocks with cam shaft diameters above 50mm require the use of Dart lifter bushings.
Standard BBC oil filter is used.
Standard BBC timing chain, timing cover, gear or belt drive can be used.
Actual deck height will be .005"- .010" taller for additional machining requirements.
Standard BBC oil pan can be used. Extra bolt holes are provided for stroker crank pan.
Cam bearing OD should be deburred before installation.
When removing main caps initially, the caps & block should be deburred before reinstalling. This will insure that correct
main size is maintained.
Standard BBC head studs or bolts may be used.
Head stud holes are blind. They do not go into the water jacket.
A sealant/antiseize must be used on the head studs. Loctite # 620 is recommended.
Studs should never be torqued into block. They should only be lightly snugged.
It is preferred that a bullet be machined on the end of the head stud where it bottoms in the block to center the stud before
tightening.