The cover on our 331 engine is a first sample from the foundry. I have more on order. I'm trying to find a seal opening that will accept seals for either Y-Block or sbc dampers. Otherwise the cover will have to be machined for a specific damper and I don't want to do that. Our plan is to shorten the steel billet Y-Block dampers. The water pump pulley can be an aluminum early sbc (there's that word again) because they are deeper than a Y-Block pulley allowing the damper and belt to be moved back farther.
The idea behind the new cover was to shorten the engine for easier installation in hot rods and to move the belts closer to the engine. This can be important on blower installations where there is additional stress on the crankshaft snout.
http://ford-y-block.com 20 miles east of San Diego, 20 miles north of Mexico