Just a quick question...  What is the difference between 18* and 23* Chevy heads?  How do you tell the difference?

Would the number on the heads tell the information needed?  I think they are "Bowtie" heads?

If they are bowtie heads then all you need is a manifold I believe the valve train all works out

Greg post some pictures here  some pictures of some bows in my shop the ex port are all the same now if you have sb2b heads or real race heads there split ex ports and intake like Cleve ford has and dizzz is in front they got it right finally and know longer  to be in
the performance parts,  the heads in the picture have the guides moved or off set for a bigger valves and to help in the push rod set up they will use split guide plates or two piece, picture of the headers to would help the chamber in these heads have been laid back to.

do you have pictures of the Stahl flanged headers to the Chevy Heads. am not
up on them  any small block header that is port matched to heads will
work i f the ex port is opened up to same size.

thems are 23 deg heads 18deg are mostly after market heads and 5 deg is not

that mutch in header deg he probley has + or - 2 deg in his jig.  and 10 deg if made

mexico or chino.