Hi Shane. I maybe wrong but I have 2 types of heads that fit the W5 engine. One normal and one higher compression as it has less combustion chamber than the one I took of my original engine. I was told it was Hp when I purchased it. When building my engine I then went and shaved it some more by 40thou and it was a rocket with cam to match. Unfortunately the block had minor cracks that didn't seal in it and rendered it unusable. but on the bright side.... it would cruise easy at 55mph before it started to play up with the cracks causing temp issues. So I put in my $50 ebay special 1965 rebuilt new engine in it. A bit slower but still good for 50mph cruising. I'll take a pic and email it to you soon. I have another block now so am going to put the guts into it and build a 2 seater speedster in the future.
Catch Ya

Kevin
0417231143

Where Are You From? Portland

Do You own a car built by Durant? D40 Tourer 1929

Good luck with those projects, That's great!.. Those a Model A and T H.C. heads took years to perfect and still not perfect...Always being tweaked because of performance and casting issues . Just less as time goes on.
Once you get 25,000 miles proven and 5 years aging on a head design...I'll buy one.
So get rolling !

D.M.S

Where Are You From? Ct

Do You own a car built by Durant? '23 Star Touring