"...The 350 HO had 2.11/1.77 intake/exhaust valves and were code #18 for 68 and #48 in 69..."



Not to split hairs, but just to try and keep all the engine info facts straight, all the sources I can find, say the #18 '68 350HO heads had small valves and press-in studs. So, basically, about the only difference between those and the #17 2-barrel heads, was the chamber size, and maybe valve spring pressure ? If I'm wrong, then I stand corrected.

http://www.antiquecarparts.net/tech04.htm

http://ronspontiacpage.com/reference-pages/stockheadspecs.htm

http://www.classicpontiac.org/FAQ.asp?myPage=V8HeadInfo

http://www.bassettracing.cz28.com/custom3.html

http://www.wallaceracing.com/headsearch.htm