Need Help w/W2 Identification

I have a set of W2 heads that I need help identifying from the attached pictures. The previous owner ground off all of the exterior cast numbers. The casting number is still present on the inside of the head, but I believe that same casting was used for a couple of different PNs. There's a 4 digit number stamped on the end of the heads too but I'm not sure if that is something that someone added. I'm a total newbie to W2s so any help would be appreciated. Thanks!

Also, in the parts deal I got a 340 block dated coded 6-20-67. I imagine that's pretty damn early in the run for the 68 model year. Anyone happen to know what the first production date for the 340 block was?

Those are unported race W-2 reads.. the econo W-2 will have a cradle ground in for the rocker
shaft.. forget the number in the inside(oil area).. that is just a casting number.. as to the first
year of the 340.. I THINK that was 67 so that would be a early one
EDIT
I would think those are the long valve version.. which I think all the race versions are.. the econos
have both the long and short versions

Want to sell that block.. PM me if its a stock deck height

I’m going to say they’re either P5249769 or P5007355

Fast could be correct with those P/Ns... there is one other P/N but I dont think so..P5249770
this is a 55cc chamber

I had a set of those only Duster back in the mid 80's. When you get rocker shafts for them, make sure the oiling holes line up to the arm hole when the valve is closed. The mothership screwed up on them and didn't correct the issue. I got shafts from Ed Hamburger, before he went GM, and they were wrong too[ probably just reboxed mopar]. I found out the hardway that the holes only lined up when the arm was almost vertical. Tatered some bushed rockers and pushrods. Found out from a knowledgeable source that it was a factory screwup that didn't get resolved. If you get rollers from someone with shafts you will probably be ok. At the time, you could get bushed or non bushed iron units from Mopar or Norris made a really nice set of stainless rollers with shafts but like a dummy I didn't get those. Could have gotten a smoking price too since my boss bought direct from Norris. The pushrods, at that time, were the semi finished ones that you cut down, after measuring what you needed, then pressed in the cup end for the rocker screw.

I read somewhere that the heads that have the extra ribs around the lower head bolt holes are later castings, I do not know how true that is.

Yes the support ribs were from a revision. Older versions also wouldnt have had the dual bolt pattern. Now, what constitutes "early" vs. "late" is up for debate. Ive never gotten a straight answer on that and W2s were produced for a long time.

Also looks like someone has ground away the "Mopar" and "W-2". Maybe to disguise them.

Very likely they were intended for FAST racing or another class that requires a "stock" appearance.

To me I would say that any W2 head with the external ribs is a later, revised casting. As we know, they often had the closed chamber as well, although there were some of the later castings that had an open chamber as well.

I actually have a set of the later/ribbed open chamber W2s on the shelf

I remember dealers clearing the open chamber race version (that required pedastals) out for just over $100 ea. Was a while ago now. I bought long lave econos at the time, but sold them off down the track.

Those are a much later casting than the W2 heads I sold earlier this year. The set I had were part number 3870812 and casting number 3870810. Mine were an open chamber race head. Yours appear to be a closed chamber race head or else the heads have been milled so much that they turned an open chamber into a closed chamber. The set I had was very early production and didn't have the ribs. I also had an early 340 block. Sold it as a package deal to a guy who always wanted a W2 340 combo for his Duster. Ended up making about 600 hp on the dyno. Should be a fun street combo.

It looks like a 59 degree head. I've seen 48 degree heads that have the intake pushrod holes breaking through the intake face.

The early ones like Andy had have the exhaust side of the head looking very much like an OE head.
The “later” ones, like the OP has have the reinforcing ribs.
And then there are some in between versions where they cleaned up the exhaust side so it doesn’t really look like a stock head anymore...... but the ribs hadn’t shown up yet.

I hadn't seen that version before. I think I like it best from just a looks standpoint. Nice clean looking casting. The early ones look like ugly factory castings and I'm not fond of the ribbed design either. The middle one with the smooth casting looks more like an aftermarket design.

I believe the “smooth” ones were very crack prone out along that lower region....... which is why the ribs were added...... to stiffen that area of the casting.

The W2 aficionados can probably speak to that.

The blue set was purchased from McCandless back in earlier 80s for 75 dollars each...the orange set was purchase in early 90s from another racer...both are the early race head.
The blue set were used on several engines thru the years and are awaiting a rebirth...the orange ones were sold at MATS several years ago at a nice profit.....lol

There is also a picture of the later set there too....they are all 59 degree heads with open chambers,,,,,

Interestingly....... the blue and orange heads have different exhaust bolt patterns.

And the last pic with the newer head has bolt exhaust port patterns...lol