How can I determine head cu's?

Hi everyone! This is my first post. Very confusing site so far. I am having a terrible time finding a replacement exhaust/intake manifold. I think part of the problem is that I am not sure if the head is a 230 or a 250. I got this van in 1973 and a mechanic changed the head. I think he put on a 250. I do know that the 3/4 plugs are too big. I have to use the 5/8. Does this mean it is not a 230?
Secondly, since I cannot locate a manifold, can I put headers on? I looked at some online today and I can't understand how they work. What happens to the intake part of the manifold? The carburetor "box", on the intake part of the manifold bolts up to the exhaust part of the manifold. Of course there is no place to do this with a header - so how does that work? Is this even possible?

Scott the heads on the chevy 6's are interchangeable between all the different engine sizes. The cubic inch sizing is determined by the bore and stroke of the motor. If you go with headers you'll probably need to go with an after market intake also, there are several brands available, stove bolt and clifford are two of the more popular ones. Check the local junk yards and you should be able to find a manifold. A 194,230,250, or 292 cubic inch should work.

if you really want headers, you need shorties like cliffords for around $400.00. long tube headers are listed to fit our vans but are way to low a better choice would be langdons for less than $300.00 you need to install a heat plate and run water to heat the intake. if you just want it fixed, do as others suggested and call a few junkyards or check craigslist, theyre out there.

[quote="donivan65"][size=18]Those 6 cylinder Chevy heads come in 2 flavors,,,,the older ones have separate intake and exhaust, (like this picture)manifolds,,,,,the newer ones, after 1980, only have an exhaust manifold,,,,,the intake is built into the head,,,Do you really need both manifolds? Headers just hook up to the 6 exhaust ports,,,,they sit under the intake manifold.......Ask whatever is confusing you about this site and we will explain it so you will have no more problems with it.....


Thank you for your reply. I want to reply back to this post only. Not sure of the direct path to do that. I have clicked on the "quote" button. I tried first to click on your email address. The field in which to type my message is black - I could not see the text I was typing - hence the "quote" button route....Regarding my exhaust/intake issue. I only need to replace the exhaust - BUT the intake bolts to it. How is that issue resolved if I install a exhaust header? In your picture (I am almost certain it is the same part I need) the two threaded posts that are shown is where the intake bolts to the exhaust - that is where the carb sits. Again, my intake is fine and I have a new carburetor. As I learn more it seems I have two options: keep looking for a exhaust manifold or install a exhaust manifold, and a intake manifold and a new carburetor. Am I getting this correct? Again, thank you.

Thank you for your reply. I want to reply back to this post only. Not sure of the direct path to do that. I have clicked on the "quote" button. I tried first to click on your email address. The field in which to type my message is black - I could not see the text I was typing - hence the "quote" button route....Regarding my exhaust/intake issue. I only need to replace the exhaust - BUT the intake bolts to it. How is that issue resolved if I install a exhaust header? In your picture (I am almost certain it is the same part I need) the two threaded posts that are shown is where the intake bolts to the exhaust - that is where the carb sits. Again, my intake is fine and I have a new carburetor. As I learn more it seems I have two options: keep looking for a exhaust manifold or install a exhaust manifold, and a intake manifold and a new carburetor. Am I getting this correct? Again, thank you.

[quote="cscott"]

donivan65 wrote:Those 6 cylinder Chevy heads come in 2 flavors,,,,the older ones have separate intake and exhaust, (like this picture)manifolds,,,,,the newer ones, after 1980, only have an exhaust manifold,,,,,the intake is built into the head,,,Do you really need both manifolds? Headers just hook up to the 6 exhaust ports,,,,they sit under the intake manifold.......Ask whatever is confusing you about this site and we will explain it so you will have no more problems with it.....


Thank you for your reply. I want to reply back to this post only. Not sure of the direct path to do that. I have clicked on the "quote" button. I tried first to click on your email address. The field in which to type my message is black - I could not see the text I was typing - hence the "quote" button route....Regarding my exhaust/intake issue. I only need to replace the exhaust - BUT the intake bolts to it. How is that issue resolved if I install a exhaust header? In your picture (I am almost certain it is the same part I need) the two threaded posts that are shown is where the intake bolts to the exhaust - that is where the carb sits. Again, my intake is fine and I have a new carburetor. As I learn more it seems I have two options: keep looking for a exhaust manifold or install a exhaust manifold, and a intake manifold and a new carburetor. Am I getting this correct? Again, thank you.

Lets talk about this QUOTE THING,,,,,I just clicked on QUOTE on your message, I go down and find the end of the very last thing you wrote and I started typing this message right after it,,,,,thats it,,,,Press Preview to see how it changes it and Send it if you like what you see,,,,,,This QUOTE thing is a REALLY GOOD way to go back and reply to a certain post that you want to talk about.......

I have taken a second look at the pictures you sent earlier. Whatever year my van's head is - your manifold picture looks like my manifold. The placement of the threaded bolts is the same and if you turn the manifold over - the two middle ports are divided - into two compartments. Correct?

The 3 bolt configuration manifold has the pipe oriented in a whole different direction and I would have to have my pipe bent to accommodate.

I sent that manifold back, thinking it was too much hassle. Today a manifold that will fit - according to pictures AND measurements, is being shipped. It's off a 250, so I guess my head is a 250. Still not sure of the year....