I have been rebuilding a 292 Y Block.  Once the intake manifold is put on there are two round holes left exposed as well as 2 bolt hole.  One each side.  I have 2 other intake manifolds and they are the same.  The spare engine I have had a temp sending unit in it and the other side looked like a factory plug was installed, like a small freeze out.  Am I missing something?  Is there a crossover pipe.  The passenger side would have to be small as not to interfere with the distributor. 

If im looking at it correctly, that is for a freeze plug or temp sender, depending on side.  The drivers side has an insert that goes in the hole for the temp sender, and just a short bolt goes int he bolt hole.  I beleive the pass side has a freeze plug and bolt as well.

Ron Grove

Wauconda, IL

Freeze plug goes in one, and a threaded (ID) bung for a sending unit goes into the other. The freeze plug is a bastard size and a PIA to find in the fractional dimension (can't recall size, at the moment, 11/64 (?) but much easier if you convert the size to millimeters- don't ask how I know this. Just run a SHORT bolt in the bolt holes- they're open to the inside of the motor, and the bolts keep icky stuff out... /Duck

BOO- YA!!!

The hole in the head is .910" so you use a 29/32" freeze plug.

What is that in 1/1000's of a yard stick?

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

22.6219mm ..../Duck

BOO- YA!!!

Duck and others, i have been using 23 mm freeze plugs here for years, no problems.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Make sure you don't have the heads on the wrong side.


Lawrenceville, GA

Didn't see it mentioned but if you use too long of bolts in the threaded holes you will bend a couple of push rods. Like Duck mentioned, use SHORT bolts.



By the way, Welcome to the Site...

BOB

I think Charlie has nailed it.  The heads have been switched side for side, therefore the water passages in the front will have one severely restricted and one blocked entirely.  Better pull the intake and verify it before going any farther.

John - "The Hoosier Hurricane"

i bought a set of used heads and when i got them home i saw they were not a match.somewhere along the line they changed one head and put on one from the opposite side.they put the freeze plug in the back as you couldnt miss it but left the one in the front in place.the intake covered it over and they ran it like that.must have been the hottest rig in town.