Identification of Genuine P400 cylinder heads

[Doc Davey]

Gday guys, I have a new P400 purchased from a supplier in Sydney Aust and just seeking to confirm the heads are genuine P400 as I cannot find any identification markings and am told P400 should be stamped on the ends of the heads also it has a single thermostat housing and an have been told P400's only have dual housings hmmmm appreciate your comment also were bolting up a 4l80E and need a TPS as it has a mechanical FIP.

 

[Will L.]

Welcome Doc. The thermostat housing is interchangeable fitting what application you want. The P 400 is most quickly identifiable by the lower end structure above the pan and below the block.

 

[Doc Davey]

Welcome Doc. The thermostat housing is interchangeable fitting what application you want. The P 400 is most quickly identifiable by the lower end structure above the pan and below the block.

Thanks Will, the block is a P400 with the girdle section and P400 markings also, the heads have no markings and I'm seeking information that will help me identify that the heads are indeed the P400 as we have had a couple of reports of substitute heads being supplied etc and of course the Chinese knock offs are ever present as are unscrupulous suppliers unfortunately. AM General advised by e mail that the P400 only come out with the upgraded duel t/stat housing etc and as our engine has the single housing suspicisions of foul play have surfaced. Have sourced comment on heads from AM but no reply as yet, I believe the engine was originally sourced from 65 engine parts near New York,we purchased the other P400 we have from these people and no problems with that one have surfaced.Hopefully we will clear up the grey areas and move on with the project.
We have another P 400 and the heads have P400 stamped on the ends we found this morning. Any clues much appreciated

 

[Will L.]

Sorry, I don't know how I missed where you wrote heads.
The AMGeneral only sending them with dual stats confuses me, as I was recently on a USMC base where 4 swaps were being done, and all 4 came out of the metal containers with singles on them. It's something I was looking at closely as they were slightly different then the single stat crossover in my hummer and I am unhappy with how my hose is routed. I've had problems with it chaffing over the years.

Could be special requests for that application.

The heads I've seen all had the p400 cast into the head.