273 4bbl intake manifold question

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Litz

Litz

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A bought a 65 Valiant Signet a month or so ago. 273 2bbl and 904 trans. The engine was gone through approx 20000 mi. ago. I want to go with headers, a cam, and 4bbl intake, and carb but am having a very hard time locating an intake manifold. I am hoping to get some suggestions from you guys on the forum. (on the cam, intake,carb, and headers) The car will have an 8 7/5 rear and 4:10 gear. Thanks in advance, Litz
 
First, verify what heads are on the engine now. Pull the valve covers and get a casting number.

64 - 65 had a unique intake bolt angle and smaller diameter bolts than the "standard" 66 and later engines...

The 64 - 65 heads are hard to get intakes for.

I would recommend replacing the heads with a set of 66 and later heads and have hardened seats installed on the exhaust valves. Then you can get any intake for the LA series engine...

The 273 - 318 has the "smaller port" heads where the 340 - 360 have larger port heads and bigger valves... However the combustion chambers on the 340 - 360 mheads are larger and will lower compression about one point if you put them on. Then the intake valve clearance to the block is tight. Not much room to put larger valves in the 273 unless you "notch" the bore for valve clearance, and then may get some shouding.

You need to provide more info for any cam, or intake and header recommendations. Like what do you plan to do with the car? Street, strip, cruiser, or race???
 
krazykuda said:
First, verify what heads are on the engine now. Pull the valve covers and get a casting number.

64 - 65 had a unique intake bolt angle and smaller diameter bolts than the "standard" 66 and later engines...

The 64 - 65 heads are hard to get intakes for.

I would recommend replacing the heads with a set of 66 and later heads and have hardened seats installed on the exhaust valves. Then you can get any intake for the LA series engine...

The 273 - 318 has the "smaller port" heads where the 340 - 360 have larger port heads and bigger valves... However the combustion chambers on the 340 - 360 mheads are larger and will lower compression about one point if you put them on. Then the intake valve clearance to the block is tight. Not much room to put larger valves in the 273 unless you "notch" the bore for valve clearance, and then may get some shouding.

You need to provide more info for any cam, or intake and header recommendations. Like what do you plan to do with the car? Street, strip, cruiser, or race???
Click to expand...
The car will be a street/strip car. Mostly street. Not a daily driver. Not sure of what cam, or intake. Looking for suggestions. Also will be looking for converter info. Not sure what's available for the 904. Thought about going to a 360 TF but the little 273 is pretty fresh and runs fine so I thought I'd play around with it for a while.
 
krazykuda said:
First, verify what heads are on the engine now. Pull the valve covers and get a casting number.

64 - 65 had a unique intake bolt angle and smaller diameter bolts than the "standard" 66 and later engines...

The 64 - 65 heads are hard to get intakes for.

I would recommend replacing the heads with a set of 66 and later heads and have hardened seats installed on the exhaust valves. Then you can get any intake for the LA series engine...

The 273 - 318 has the "smaller port" heads where the 340 - 360 have larger port heads and bigger valves... However the combustion chambers on the 340 - 360 mheads are larger and will lower compression about one point if you put them on. Then the intake valve clearance to the block is tight. Not much room to put larger valves in the 273 unless you "notch" the bore for valve clearance, and then may get some shouding.

You need to provide more info for any cam, or intake and header recommendations. Like what do you plan to do with the car? Street, strip, cruiser, or race???
Click to expand...
 
Litz said:
The heads are 65 heads
2465315
Click to expand...

Thke best intake for those heads is the obsolete Edelbrock D4B... It is made for that unique bolt angle and size, but are hard to find and fetch a good price when found...

If you put 66 and later 273-318 heads on it, then your intake selection has much more possibilities...

The Wiand stealth intake would be a great intake for that engine with later heads, good from idle to 6800 rpm...

Weiand 8022WND Weiand Stealth™ Intake - Chrysler Small Block V8 - Holley Performance Products
 
The 64-65 heads take the Edelbrock D4B...

The 66 and later 273-318 heads take the Edelbrock LD4B...

The 340-360 heads take the Edelbrock LD340...

Just for clarification.... :D
 
Litz said:
The heads are 65 heads
2465315
Click to expand...

Is the cam in your engine hydraulic or solid lifter??

Stock cams in those were solid lifter with adjustable rocker arms...

Take a picture with the valve cover off and post it...

And does it tick when running or silent???
 
I thought it said D4B? It actaully says D4B on the back and LD4B on the front?? Odd.....

Jake
 
xLURKxDOGx said:
I thought it said D4B? It actaully says D4B on the back and LD4B on the front?? Odd.....

Jake
Click to expand...

You're right now that you mention it...

I saw the LD4B on the one picture and assumed it was an LD4B...

The seller should check for the bolt size...
 
Drilling the bolt holes in the more common aluminum intake to match those early LA heads has been done a bunch of times over the years.
 
krazykuda said:
Is the cam in your engine hydraulic or solid lifter??

Stock cams in those were solid lifter with adjustable rocker arms...

Take a picture with the valve cover off and post it...

And does it tick when running or silent???
Click to expand...
The car has a solid lifter cam
 
krazykuda said:
Thke best intake for those heads is the obsolete Edelbrock D4B... It is made for that unique bolt angle and size, but are hard to find and fetch a good price when found...

If you put 66 and later 273-318 heads on it, then your intake selection has much more possibilities...

The Wiand stealth intake would be a great intake for that engine with later heads, good from idle to 6800 rpm...

Weiand 8022WND Weiand Stealth™ Intake - Chrysler Small Block V8 - Holley Performance Products
Click to expand...
If I use 66 or later heads I will have to notch the cylinders for intake valve clearance? Or do I only have to do this only if I use aftermarket larger valves? Also can I mill the heads to get the compression back to stock specs? Sorry for all the questions but I'm new to the smallblocks and pretty ignorant to the parts swapping. Thank you for all the info. Litz
 
Litz said:
If I use 66 or later heads I will have to notch the cylinders for intake valve clearance? Or do I only have to do this only if I use aftermarket larger valves? Also can I mill the heads to get the compression back to stock specs? Sorry for all the questions but I'm new to the smallblocks and pretty ignorant to the parts swapping. Thank you for all the info. Litz
Click to expand...
66 or later 318 heads only. The 340 and 360 heads have larger combustion chambers and vales that aren't friendly with the small bore of the 273. They also have larger ports that also don't match up with the 273 intake and exhaust ports.
 
krazykuda said:
You're right now that you mention it...

I saw the LD4B on the one picture and assumed it was an LD4B...

The seller should check for the bolt size...
Click to expand...
Can someone run the number on the net and see what it is? I am leaving for church. lol
 
Litz said:
If I use 66 or later heads I will have to notch the cylinders for intake valve clearance? Or do I only have to do this only if I use aftermarket larger valves? Also can I mill the heads to get the compression back to stock specs? Sorry for all the questions but I'm new to the smallblocks and pretty ignorant to the parts swapping. Thank you for all the info. Litz
Click to expand...

No, the 66 and later 273-318 heads have the same size valves in the same position as the early ones, just the later intake bolt size and angle... The combustion chamber size should be close if not the same as what you have now...

If you put 340-360 heads on there, they will have larger valves and larger combustion chambers that will lower the compression...

I would recommend using the 66-67 273 head, it has the closed chambers on them and the proper intake bolt pattern...

Here's a set of 67 920 heads that I had done up by my head guy. They are for my son's 318 in his Challenger and my head guy did them up with the 360 valves and ported them... They have the smaller closed chamber for higher compression... You can get away with larger valves on the 318 because of the larger bore, but not recommended for the 273...

But if you get a set of these, they will go on and you can use the Edelbrock LD4B intake with them... (You will have to re-mount the coil somewhere as the manifold does not have the bosses to put it in the stock position. One moderator here had a clever solution to use a 340 six pack coil mounting bracket and it worked very nicely...

You would want to look for these casting numbers for those type of heads, they are for 66-67 273 and 67 318 heads:

2536178, 2658234, 2658920


Here's a link for the head casting number reference chart:

MyMopar - Mopar Forums & Information - Mopar Head Casting Numbers 1959-1978

DSC02015 B.jpg


DSC02018 B.jpg


DSC02011 B.jpg


DSC02022 B.jpg


DSC02027 B.jpg
 
krazykuda said:
No, the 66 and later 273-318 heads have the same size valves in the same position as the early ones, just the later intake bolt size and angle... The combustion chamber size should be close if not the same as what you have now...

If you put 340-360 heads on there, they will have larger valves and larger combustion chambers that will lower the compression...

I would recommend using the 66-67 273 head, it has the closed chambers on them and the proper intake bolt pattern...

Here's a set of 67 920 heads that I had done up by my head guy. They are for my son's 318 in his Challenger and my head guy did them up with the 360 valves and ported them... They have the smaller closed chamber for higher compression... You can get away with larger valves on the 318 because of the larger bore, but not recommended for the 273...

But if you get a set of these, they will go on and you can use the Edelbrock LD4B intake with them... (You will have to re-mount the coil somewhere as the manifold does not have the bosses to put it in the stock position. One moderator here had a clever solution to use a 340 six pack coil mounting bracket and it worked very nicely... Thank you for all the info. I really appreciate it. If I am lucky enough to locate a set of heads that you recommended will I still need to clearance the cylinder (Intake valve) or will they be ok to run "as is" I'm assuming they will be OK? I've had several B/RB engine B body cars but this is my first A body small block. I think you have me going in the right direction. Thanks again! Litz

You would want to look for these casting numbers for those type of heads, they are for 66-67 273 and 67 318 heads:

2536178, 2658234, 2658920


Here's a link for the head casting number reference chart:

MyMopar - Mopar Forums & Information - Mopar Head Casting Numbers 1959-1978

View attachment 1714984333

View attachment 1714984334

View attachment 1714984335

View attachment 1714984336

View attachment 1714984337
Click to expand...
krazykuda said:
No, the 66 and later 273-318 heads have the same size valves in the same position as the early ones, just the later intake bolt size and angle... The combustion chamber size should be close if not the same as what you have now...

If you put 340-360 heads on there, they will have larger valves and larger combustion chambers that will lower the compression...

I would recommend using the 66-67 273 head, it has the closed chambers on them and the proper intake bolt pattern...

Here's a set of 67 920 heads that I had done up by my head guy. They are for my son's 318 in his Challenger and my head guy did them up with the 360 valves and ported them... They have the smaller closed chamber for higher compression... You can get away with larger valves on the 318 because of the larger bore, but not recommended for the 273...

But if you get a set of these, they will go on and you can use the Edelbrock LD4B intake with them... (You will have to re-mount the coil somewhere as the manifold does not have the bosses to put it in the stock position. One moderator here had a clever solution to use a 340 six pack coil mounting bracket and it worked very nicely...

You would want to look for these casting numbers for those type of heads, they are for 66-67 273 and 67 318 heads:

2536178, 2658234, 2658920


Here's a link for the head casting number reference chart:

MyMopar - Mopar Forums & Information - Mopar Head Casting Numbers 1959-1978

View attachment 1714984333

View attachment 1714984334

View attachment 1714984335

View attachment 1714984336

View attachment 1714984337
Click to expand...
 
340 demon 72 said:
Bolt hole size .460 View attachment 1714984369
Click to expand...

That's over 7/16" diameter and will be plenty of clearance for the "standard" 3/8" bolts and angle...

That must be an LD4B... :thumbsup:

If I were Litz, I would buy that intake and then find a set of 2536178, 2658234, 2658920 heads locally. If he can't find any locally, I may know of a set near me...
 

I'm not sure what you are asking as there is no other text than what you are quoting from me....
 
krazykuda said:
That's over 7/16" diameter and will be plenty of clearance for the "standard" 3/8" bolts and angle...

That must be an LD4B... :thumbsup:

If I were Litz, I would buy that intake and then find a set of 2536178, 2658234, 2658920 heads locally. If he can't find any locally, I may know of a set near me...
Click to expand...

Another option for him is to try the LD4B as is and see if the bolts will work, if not, he can enlarge the hole diameter a bit until it does, but that's a band-aid and I don't like to do that if I don't have to....
 
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