This is my friend's 261 in his 52. 261 was the big six before the 250 series. This one is bored 60, head shaved and professionally ported by another friend who ports racing heads. Dual Holley-Weber progressive 2 barrels, offy intake, full race cam, cast Fenton headers, Unilite distributor with MSD-6. Very streetable, but wicked. This engine's factory redline was 3,600 rpm, he has turned over 6,000. Running pump gas I would guess he's around 250 hp.
Parts for the older sixes are available at
www.patricksantiquecars.com and
www.stoveboltengineco.com