It has been a while since I was messing with SBC stuff fitted to Y.  But as I recall the stock length of the stainless valves would either be the same as Y, or +-.050.  Whether longer or shorter, it could be worked with in a rebuild to replace a 1.78 in. intake, or like even a 1.64 intake.

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

The description of the valves is thin.. no length given etc. Are they simmilar to the ones Mummert sells? His 1.84 valves are intended to replace the very small truck or late valves that Ford issued for the Y-Block. His likely fit the S. American heads that Dennis Carpenter was selling also.

Paul

Speedway has these 1.84 in. intake valves on closeout for $6 ea FYI.  http://www.speedwaymotors.com/Garage-Sale-Intake-Valve-184-Stock-Length,49081.html 

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.