Cant go by your picture. Need the casting number as Kevin mentioned.

Thanks,
I was hoping maybe someone whew of a pattern match.
I will look under the cover.

It's possibly a 1969 307 head or for a 1969 327 210hp (small 2BBL from Camaro) or 235hp (large 2BBL for full size). It is the 1969-70 equivalent of the 1968 3911032 (McKinnon 307 head) and the 3917290 (Tonawanda 307/327 head). These are both 69/70cc small port, 1.72/1.5 valve heads. As the casting mark is rough cast it will probably be a Tonawanda or McKinnon machined head, so possibly a 3927185 which is probably McKinnon cast as I don't think Tonawanda cast this head.

However the angle on the sides of the mark suggest another possibility. That casting mark was used across a number of heads from 1971-1974. Used on:

3973487 which is a 76cc version of the old fuellie head, used in both 1.94/1.5 and 2.02/1.6 valve versions.
3973487X (as above).
3986316 different chamber design and only 2.02/1.6.
3998916 basically as per below but only in 2.02/1.6
3998993 replaces 3973487. 76cc with either 1.94/1.5 or 2.02/1.6.

Most of those are early 70's Z28 or Corvette.

the plugs are 5/8