Quick question, is there any way to ID a 300 head for sure without removing it?

My 86 Bronco came with the feedback carb and all, but when I swapped on a pair of EFI exhaust manifold there were 16 bolt holes. Is it possible an EFI head was used on a late-run carbed vehicle?

I'm about to start seriously looking for a head core. I want one with the machined pushrod slots and studs, so if I've got an EFI head now I reckon I'll need a 240 head to keep the compression. Other than pulling the head how can I be sure?

 

HGB4x4 also had 16 bolt holes in his '86 head. I believe everything else in it was the same as the carb head though.

We figured that they were switching over their tooling to get ready for the 87 year when the EFI hit. Some carb heads just got drilled for 16 bolt holes, even though only 13 were used.

Did you take pictures of your chambers before installing the head? I believe you can visually see the difference between the two by how they're shaped.

 

The head #'s should be stamped under the stat outlet.

240 head:



300 chamber:

 

Well I've never had the head off, so no clue on the chambers.

I reckon I'll probably just get a 240 head. If I've got a carb head I'll pick up some compression, if it's EFI I won't be losing any.

 

You mean on the front of the head towards the radiator or on the underside? I just changed the thermostat not to long ago and don't remember seeing anything on the front side. Of course, I wasn't really looking for casting nos. at the time.

 

Directly under the thermostat housing, there's a lip that has the casting numbers on it. You can see the spot where they'll be in this picture, directly above the top bolt hole on the water pump opening (on the passenger side).

 

Oy vey, I don't think there's any way to even get a mirror in there to try and look on my truck. I've got a line on a 240 head, so I think that's the way I'm going.

 

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I have 2 of there motors one in and one out of the truck! There are no markings anywhere around the thermostat housing ether beside or under but.......... I did find what look like "casting" nos in the very front under the valve cover, mine reads "3e17" and there is also a circle of nos between the first 2 valves. Both were "cast" and not stamped into the head. I am thinking that this is where they are decause I cannot see any other nos anywhere on either of them.


QUOTE=BaronVonAutomatc;9999377]You mean on the front of the head towards the radiator or on the underside? I just changed the thermostat not to long ago and don't remember seeing anything on the front side. Of course, I wasn't really looking for casting nos. at the time.[/QUOTE]

 

On the left side of this pic. This pic is rotated clockwise 1/4 turn and the numbers on this particular head have been milled down but that's where they are.
You are right, it would be hard to see while still installed but try this.
Use your phone and try to get the best angle pic that you can get. Then zoom in. I use this technique often when I can't get a proper angle for my eyes to see something. That or when I'm reading a blueprint and have forgotten my glasses.

 

I've used this trick quite a few times. Also great for getting a look at something that doesn't have the room to get your head in.