452 casting

hello,
picked up a pair of "452" b/b heads for my stocker, has a 1/8" pipe plug on one end. is this factory? motor home?? never seen this before. also appear to be surfaced quite a bit, casting numbers on deck surface top 1/16th have been machined. deck thickness on lower head bolts is 1.00 thick, what's unsurfaced thickness?

What kind of spark plugs do those heads use? I’ve heard that uncut heads measure a little over 1”, but I’ve never measured personally

Are there steam ports at the exhaust valves? There are two 452 heads. Standard and motor home.

There was someone in Westchester NY selling bare NOS 452 heads on Craigslist or facebook a few months ago. $50 ea. I believe they had 3 pair. I searched but can’t find them now. If I find them I’ll let you know. They were within a 1/2 hr for me.

I’ll check my heads for that plug but I don’t remember one being there, might be wrong though.

906's usually measure 1.00ish from the factory ,I never measured the set I had gotten from Paul Rossi back in the 80's , they were NOS castings , small plug with the water ports around the spark plugs.

What's the depth of the open part of the chamber , the set I had were over .100 , as deep as .130 in the center of the head.

The 1/8" pipe plug is factory and I believe to be only on motorhome heads. I just sold a set like that a few weeks ago. I removed them from a 440 that came out of a motorhome.

regular spark plug no taper, no steam holes, chamber depth measures .063
was there a calculation for surface milling for cc reduction?

The outer head bolt row is usually a reliable indicator for head milling.

Uncut heads will be right about 1.00” thick.

Yeah, one inch is what I used to use as the gauge when I bought and sold cast iron heads. If the calipers read 1.00 or higher I assumed they were uncut heads. I can't say I've ever seen a factory drawing for the heads but it seems to be a good rule of thumb.

.063 says to me it's been cut , I've never seen an open chamber head that shallow... is the open part of the chamber floor parallel to the deck surface ? That almost looks angle milled , which I've never heard being done to a big block wedge head?

casting area by number is at a angle chamber is flat

The one set of NOS castings I had , the Paul Rossi heads , were the peanut plug /extra cooling holes version and the chambers were .110 to . 130 deep.

CC the head , if it's less than 90-92 cc it's been cut.

Starting to sound like these are some type of motorhome heads. The 452 heads I used on my 440 doesn’t have that boss drilled and tapped. It also took flat/gasket spark plugs

I have a few with the plug and also steam holes in th deck, it seems it was for the HD application, RV's, trucks and police cars. S/F....Ken M