1965 273 Intake Manifold question

[dragnknights]

Hello,
I just picked up a 1965 barracuda with a 273 commando in it. It leaks unbelievably bad from the front and the rear of the intake manifold. I heard that the 1965 273s have a little bit different heads than 66' and up. Could the leak be resultant of using a later aftermarket intake manifold on an early 273 or is it more likely that the previous owner didn't use RTV to seal the front and rear surfaces of the intake manifold? Any advice would be great! Thank you!

 

[Wyrmrider]

Or p o could have been running water in it and rotted it out
btw are you leaking oil or water

 

[toolmanmike]

What intake is on it?

 

[dragnknights]

Or p o could have been running water in it and rotted it out
btw are you leaking oil or water

Leaking oil. No Water

 

[dragnknights]

What intake is on it?

Looks like one of those Chinese air gaps. I haven't seen any markings on it.

 

[dragnknights]

In theory though, would a later intake manifold fit an early 273?

 

[toolmanmike]

65 heads accept their own intake unless the bolt holes have been modified. 64 and 65 273 had smaller bolts at different angle than the 66 and newer.

 

[dragnknights]

65 heads accept their own intake unless the bolt holes have been modified. 64 and 65 273 had smaller bolts at different angle than the 66 and newer.

 

[dragnknights]

Ok, so I'll need to get an original intake manifold or possibly modify the bolt holes on the one I have?

 

[chryslerfat]

Ok, so I'll need to get an original intake manifold or possibly modify the bolt holes on the one I have?

Are your bolts 5/16 which is 64 and 65 or 3/8 whiuch is 66 and newer? The 5/16 is usually a 1/2 head and the 3/8 is a 9/16 head. That will tell you what heads are on it.

 

[krazykuda]

Hello,
I just picked up a 1965 barracuda with a 273 commando in it. It leaks unbelievably bad from the front and the rear of the intake manifold. I heard that the 1965 273s have a little bit different heads than 66' and up. Could the leak be resultant of using a later aftermarket intake manifold on an early 273 or is it more likely that the previous owner didn't use RTV to seal the front and rear surfaces of the intake manifold? Any advice would be great! Thank you!

The geometry of the heads and intake are the same for all 273's, just the intake bolt holes are a different angle and smaller diameter... The intake should fit, just the bolt holes may not line up properly...

You say that it's leaking from the front and real of the intake... I would remove the intake and check to see if the intake has clearance holes for the pins that hold the flat gaskets in the front and rear of the block in place... If the intake does not have any clearance holes, it may be the pins not allowing the intake to seat... Either drill clearance holes where the witness marks are on the intake from being tightened down with the pins on it, or remove the pins... I would drill clearance holes if it were mine as I like to have the pins in the front and rear of the block to keep the gasket better lined up and not squish out of alignment when tightening the intake....

 

[Richard Sweet]

Ok, so I'll need to get an original intake manifold or possibly modify the bolt holes on the one I have?

Yes, start there, then see how the bolt holes line up between the I.M. and the heads and how much gap there is between the front and rear bottoms of the I.M.. You might need to use different I.M. gaskets or determine if there needs to be some milling done to the heads or even the I.M. surface. You might just need to enlarge the I.M. mounting holes. This can be determined by doing dry mounting the I.M. several times to observe the alignments and measuring the gaps at the front and rear, then enlarging the holes that don't align. When you get the I.M. mounting holes aligned, you can check the I.M. gasket alignment with the intake ports on the I.M. and heads. Be patient and take the time to get it mounted right.

 

[dragnknights]

Are your bolts 5/16 which is 64 and 65 or 3/8 whiuch is 66 and newer? The 5/16 is usually a 1/2 head and the 3/8 is a 9/16 head. That will tell you what heads are on it.

 

[dragnknights]

Guys, thank you very much for the information. So after putting the work on it this weekend, this is what I have found. Though the block is a 1965 273, the heads are later 273-318 I think from like 67-71 or something like that. The intake manifold though turned out to be a magnum intake (with the vertical bolt holes) machined for these heads. Strange I thought. Anyways the issue with the leak was no RTV was used on the quark gaskets at the front and rear. Got her back on the road and seems that the intake leaks are taken care of. Thank you all for your help! Much appreciated!

 

[Richard Sweet]

So what are the casting numbers on the heads? Also, oil leaks are more likely to come from the valve covers than from the I.M.. Check the valve cover gaskets and don't forget to do a valve adjustment too. The 273s have solid lifters, so valve adjustment is important.

 

[dragnknights]

So what are the casting numbers on the heads? Also, oil leaks are more likely to come from the valve covers than from the I.M.. Check the valve cover gaskets and don't forget to do a valve adjustment too. The 273s have solid lifters, so valve adjustment is important.

Thanks! I'll have to look the head number up again, but you're absolutely correct. Those valve covers leak like a siv!!!!!