Comp Cam 7821-16 pushrods (340 w/ 273 rockers)

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71duster06

71duster06

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Has anyone used these pushrods? Comp Cam 7821-16
In the item description they are sold as LA 273-360 "Hydraulic Lifters w/Adjustable Rocker Arms"

Any input will help. These would be used on a 1970 340 w/ stock J heads using 273 adjustable rockers. Lunati cam w/ hydraulic lifters
Comp Cams #249-7821-16

High Energy Pushrod Set
Chrysler 273-360ci 1964-86 Hydraulic Lifters w/Adjustable Rocker Arms
5/16'' Diameter
7.389'' Intake; 7.389'' Exhaust
End Type: A-C
16/pkg.
http://www.jegs.com/i/Comp+Cams/249/7821-16/10002/-1
 
Subscribed. I also have a 70 340 that came with 273 adjustable rockers and stock 273 pushrods.
 
Those are the correct pushrod for hydraulic flat tappet lifters and adjustable rockers. They are for ball type rocker adjusters, thats why the pushrod has a cup on it to accept the ball.
 
I would buy (or borrow) a push rod checker and measure it yourself. That way you know you have the right length. There are too many variables (milled deck, milled heads, base circle on the cam, etc) that can affect what length push rod you need.

FWIW, I use Smith Brothers push rods in my car. They can make a custom set for just about anything.
 
MRL Performance said:
Those are the correct pushrod for hydraulic flat tappet lifters and adjustable rockers. They are for ball type rocker adjusters, thats why the pushrod has a cup on it to accept the ball.
Click to expand...

Correct. My worry (as flyfish mentioned) is the overall length. Since my head has not been decked, and everything is in stock form, I figured that these pushrods would work length wise.
 
I bought a set of those for my stock 360 w/ stock J heads using 273 adjustable rockers a Lunati cam w/ hydraulic lifters thinking they would fit right in but they were too long. I would suggest meauring and having a set made to proper length by Manton or Smith Bros. I have used Smith Bros to build a couple of different sets for me and can recommend them.
 
grimreaper said:
I bought a set of those for my stock 360 w/ stock J heads using 273 adjustable rockers a Lunati cam w/ hydraulic lifters thinking they would fit right in but they were too long. I would suggest meauring and having a set made to proper length by Manton or Smith Bros. I have used Smith Bros to build a couple of different sets for me and can recommend them.
Click to expand...

Do you remember the rough cost to have those made?
 
I don't remember the amount but was surprised how reasonable they were and wished I had never thought of trying off the shelf pushrods and wasting that money. They will want to know your spring pressure to ensure that they are providing the correct pushrod but 5/16 should meet your requirements. I had them build a set of pushrods for my 273 with W-2 heads and high spring pressure so I was kind of expecting a similar price to those but the 5/16 they built me for my 360 were really quite reasonable. Just give them a call and they can give you a rough idea. Of course you can buy, borrow or build a length checking pushrod and get a measurement to compare aginst the length of the 7821-16s. If they are correct use them, but you really need to get a meaurement no matter how you proceed.
 
Since I plan to install a hydrolic cam/lifters in my 273 that is otherwise stock I expect the " off the shelf " pushrods to work. I sure hope so since I've already bought them.
As others have said, the farther you move from stock with the cam and heads the more things change.
I think custom length pushrods would be better than shims under the rcokers shafts.
 
You're going to want custom-length push rod's with your combo dude.

Hughes engnes was doing them $7.75/each.
 
flyfish said:
I would buy (or borrow) a push rod checker and measure it yourself. That way you know you have the right length. There are too many variables (milled deck, milled heads, base circle on the cam, etc) that can affect what length push rod you need.

FWIW, I use Smith Brothers push rods in my car. They can make a custom set for just about anything.
Click to expand...

X2
This reply is exactly what I would have advised. I used Smith Brothers also.
 
I put hydraulic lifters & a mild cam (0.422/0.444) in my 273. I got the required shorter ball-cup push-rods at Summit (~$35 I recall). I recall posting on it a few years ago (search my name) and might have listed the PN. I recall they are also listed as for the 340 TA (or whatever later LA engine had the adj. rockers). As mentioned, if you have a high-lift cam, they might be too long and you might want custom shorter ones to "split the difference" in the wild swing.
 
The last few parts that I ordered were delivered yesterday...Time to send the heads and intake to the machine shop. Let the build begin. (Hoping to get it ready for the Power Tour)
 
71duster06, what did you end up going with? I have a similar setup in my 70 dart.

I need to get some racing push rods that will hold up. Also i need to get different shafts that have two oil holes.
 
Thread is 5 years old... I am not sure if the OP is still hanging around. PM him (ooops....'start a conversation' with him) and see what you get. Or, just follow KK's more recent thread links.

You can drill the 2nd set of holes in the shafts yourself. They are straight up from the bottom holes about 75-80 degrees up around the circumference of the shaft. See pix in post #29 here:
273 rocker arm adjustment

However, that may not be the optimum location; see how YR located them: look at post #37 of the same thread.

The size of that 2nd hole on my shafts are .125" (1/8").
 
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