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.
Yeah. And guess what stroke those 440's with smallish heads that run good are using..... 3.75.
Nothing wrong with those huge strokes i guess. But on a dinky bore and will all the side loading and terrible rod ratios.... why? Especially for a race only motor. Are guys running them and naking power, sure. Just to me, that 3.80 ish stroke and a big bore seems optimal.
