What are "990" heads???
 

I have a BB with 990 square port, open chamber heads. I have not pulled the valve cover to get the complete part# but none of my books make reference to any BB heads ending in 990. Are these over the counter replacements and for what applications? I was told my 427 BB had these heads with L88 pistons. Thanks.

Re: What are "990" heads???
 

Check out "Mortec".


http://www.mortec.com/bbc.htm

You've got a pair of open chamber square port over the counter heads. Really nice heads, just not assembly line on anything.

Re: What are "990" heads???
 

mortec.com shows them as 454 service replacement heads, but they have the same chamber as the 074 alum heads.
I have a pair on my car, and they are stamped "L88" on the side. https://www.yenko.net/ubbthreads/imag...ns/naughty.gif
http://i10.photobucket.com/albums/a1...ers215/L88.jpg