4.25 stroke SBs are awesome. All the crap about the heads not being big enough out there is bull pucky. An x head flows almost what a 906 BB head does and tons of guys are running them on 440 CID engines. A decent ported eddy SB head flows about what a ported 906 does and again lots of 440s run great with 906s. A good W2 flows similar to a decent eddy BB head and again tons of guys running them on 440-512 CID engines.

The real question should be how many cubes X RPM do you want to turn. I always build the biggest bottem end the budget can aford, nothing like loafing along at low RPM and still posting great time slips.