Square port round port?

[dirtydon]

How can I tell what ports my 521 has with an l18 has without removing the ex manifold?

Thanks in advance for any info.

Dan

[71-521]

look at the head between the #2 and #3 spark plugs...it will have an ID like 210, A87, U67. that will tell us what it is...just ask or look on the 620.com under head ID