If youve had questions about integral vs. non-integral head inline 6's w/pics

[tkeduk8r]

Well I tried a post about this as a response to a post a few days back, but I figured I'd try to contribute a bit to the board instead of take so here goes.... I just happen to have both versions of the inline 6's in the shop right now, pulled and on engine stands... the orange and forst one Ill post pics of is a 1966-67 non-integrated intake 250 (like most of us have) with a power steering unit off of a 73 chevelle that I had laying around. This is representative of what the sixes in the 67-72 range would have had in them.

The second group of pics is an integrated intake 250 that I recently pulled from an 82 C10... This also has power steering on it, but the brackets are very different and will not interchange between the two (as illustrated). The integrated heads were standard on trucks beginning around '78 and have had a reputation for cracking, so they are popularly viewed as undesirable. I however have had good luck with both the integrated 250's I have owned and I think the updated technology in the carb (2BBL) and the exhaust (dual outlet) make them better performers (in stock condition vs. there older non integrated counterparts) and better at the gas pumps (i routinely got 17-19 mpg on 55 mpg trips in my 80 K5 blazer in the 90's).

Well here are the first group of pice of the NON-integrated intake 250. Notice the conventional valve cover and the single barrel Rochester Monojet. There are single bolts, threaded perpindicular to the pushrods, with unique retainers that clamp both the intake and exhaust manifold to the head.

[tkeduk8r]

NON Integrated 250 pics continued..... These illustrate the power steering brackets used on these style engines. I pulled this set up off a 73 chevelle and there must be a slight difference in water pump length simialr to the small blocks of the era because there is not enough stud length on the waterpump as well as the fan bolt spacing is a slightly smaller diameter than the older 230-250's....

[tkeduk8r]

Here is the INTEGRATED INTAKE 250 pulled from the 82 C10. The easiest ways to ID these are the valve cover that varies in height along with the four pollution control vents into the high sides of the cover, and dual outlet exhaust pipes. These come with a "staggered" 2 barrell carb as well. Notice the bolts that thread parallel to the pushrods clamping the exhaust manifold to the intake. The power steering set up came on this particular engine OEM (1982 for this one). This particular truck was also optioned with AC but the compressor and upper brackets were removed before I got the truck...

[tkeduk8r]

I hope this helps and if you have any other requests fro pics let me know and I can shoot them for you... I wont be needing these for my autos class for quite some time so they will remain complete for the time being.... Lemme know....
--Mike

[welkerbr]

Thanks so much for posting this. I'm just getting into rebuilding my 1968 GMC p/u and this answered a basic question I had. I appreciate the pictures.

[EARNHARDT#3]

The 1bbl carburetor in the picture is a Rochester B. Not a Rochester Monojet.

[tkeduk8r]

Been a while since I looked at this.... But yes it is a b not a monojet ad I thought back then.....
Mike

[welkerbr]

Thanks for the update guys. Below are a few pictures of the head that's pulled off the engine now. Casting # 3895052. One of the pictures shows what I happened during a previous rebuild circa 10-15 years ago. It looks like the casting was drilled out to accept spring pins to secure the bolts in palce. Naturally this created a stress concentration, which has now lead to the casting fracturing right at this point.

Here's a bit of background on the rebuild as well which is relevant to the story. This is the start of a nostalgic project because my father and I worked on this when I was in college. The truck has really been sitting since then and has just been rusting away. Now I've got a son and want to have the same experience with him that my father and I had together. Given my job, I'm about 700 miles away from Dad and the truck, so our communication is via phone and emailed pictures with help from Mom because Dad thinks that mice should be killed and are not useful for anything.

The current plan is to get the truck "running" again with the help of a local mechanic that Dad trusts, and then transport it out to me, so I can make some loger term decisions about what's next. I would like to do this ASAP, certainly before the snow flies, as this process is creating a bit of stress with Mom and Dad. The sooner the better, but I also think that Dad may be having some trouble letting go.

Back to the head question...I'm not sure of the purpose of these casting posts and the bolts where the damage is.
1) What are they there to secure?
2) What is the issue with using the head as-is?
3) Is there a cross reference table showing what other heads can be used as a substitute?
4) Any other recommendations about places to call to look for a head? I've called the places below and so far no-one has this exact casting number.

Mabbco - east Texas - 3895054 casting in stock
Langdon's stovebolt - Utica Michigan - 331184 in stock
Machie World - Long Island NY - nothing in stock
Clearwater cylinder head - Clearwater Florida - 3985084 in stock
Cylinder heads international - Dallas Texas - none in stock
Engine Parts Warehouse - waiting to hear back
Oscaro Parts - San Jose California - none in stock
National Cylinder heads - might have one in stock (need to send pictures)

[tkeduk8r]

well, as far as I know and after reading Leo Santucci's book on performance modifications on theinline 6's, there is minimal if any difference between cylinder heads for these engines even though the casting numbers vary. As far as I know they all had 1.72 dia intake valves and 1.50 exhaust valves... and flow the same. Also all of the non-integrated head off of a 230-250-292 will bolt on... There is a small chanber version that came in some early cars, but the odds of stumbling into one of those would be unlikely and it will still bolt on and function well on your engine.

Anyway, I wouldnt go spending a ton of money on a head from one of those shops, as im sure there are some board members near you that may have a perfectly good head laying around that wont cost you much. I have a good head here in my autoshop, but Im sure the shippping would be cost prohibitive from northern MN. I can look into it if you would like though. I have magnafluxing capabilitys here at school and it is crack free. I could also touch up the valves and seats.

In the end, with the cracking on your head I wouldnt bother with it and Id look at a rreplacement.

Hope that helps

--Mike

[mechanicalman]

Is the broken rocker boss the main reason you want a new head?

You might take it to a local machine shop and see if there is enough meat (iron) left so that they could mill the rocker bosses down and put in screw in studs with hex shoulders (no need for guide plates). They can also mill it down more if nec. and put a washer under the stud that is the thickness of a guide plate. Watch this video and you will see what I mean.

https://www.youtube.com/watch?v=thVrD5e3EUc

I assume all the rocker bosses were pinned, and all at risk for breakage.

[55dude]

does anyone have in on a 250 casting # 377127 (73-79) for application? stamped number is F92211BA thanks! integrated head 1 barrel and has 3spd attached to it. my GUESS is 79 camaro?

[MikeB]

Just want to add that the two chambers on top of the valve cover are part of the PAIR system -- Pulse Air Injection Reactor. It uses exhaust pulses instead of an AIR pump, and is a big kludge. The other side looks even worse.