what size are the freeze plugs in the heads?

[bad440]

guy i know has the freeze plugs out of the cyl heads on his 318.he bought the heads at kragens when there was a kragen.one freeze plug was rusted thru.he says he cant get the freeze plugs .i popped one out of the 340 heads on my bench(cause it will get new ones) and its a dorman p24c it will fall into the heads he has.did they have more than one size?:sign3:

 

[CPMotorworks]

1.25" Melling #18B

 

[bad440]

1.25" Melling #18B

thats the size that came out of the 340 heads and it falls thru on his heads.i guess they must have messed with somthing on his.it does have those rebuilder freeze plugs with the part that falls off if it gets too hot....

 

[waggin]

they are 1 1/4" on the heads and the front passenger side of the block(5) the other( 9) are 1 5/8" napa had the best price in my town and that is rare carquest wanted 4 and change for the big ones and almost 3# a piece for the little ones