AAR Cuda replacement lifters and pushrods

[rusty409]

I recently had to replace the lifters and pushrods in my AAR Cuda.
The original part numbers are:
lifter 3577092
pushrod 3577121 length 7.250 diameter 0.375
After a lot of research and searching, I ended up replacing them with lifter COMP Cams Pro Magnum Hydraulic Lifters 862-16 and pushrod Summit Racing Pushrods SUM-G6420 Overall Length 7.389 and Diameter 5/16 in (0.313).
I had no issue stetting the valve lash and it seems to run well.
Currently I have the carbs off, just had them restored by Harms. If I got it wrong, I am at a great spot to change them. Anybody have any comments on the parts that I used or any suggestions on alternate parts to use?
Thanks

 

[Steve340]

Generally replacing lifters only a flat tappet cam could cause cam lobe wear.
Careful inspection of all the cam lobes. If OK you may have dodged the bullet.

 

[rusty409]

Generally replacing lifters only a flat tappet cam could cause cam lobe wear.
Careful inspection of all the cam lobes. If OK you may have dodged the bullet.

Thanks for the info. Hopefully it's ok. I'm using high zinc oil, prelubed the lifters in high zinc oil, used assembly lube, and broke them in like I would on a new cam. I'll check the lash and lift to see there are any issues.

 

[Steve340]

I had another think about your engine. You didn't say but I assume the AAR still has the 340 in it.
Due to the angle of the lifter bores measuring the valve lift is tricky on the small block. With the heads and the intake on it was impossible to get any consistency of measurement.
Just a thought you might be better to leave well enough alone and see what happens.
What is done is done if you get my meaning.

 

[rusty409]

I had another think about your engine. You didn't say but I assume the AAR still has the 340 in it.
Due to the angle of the lifter bores measuring the valve lift is tricky on the small block. With the heads and the intake on it was impossible to get any consistency of measurement.
Just a thought you might be better to leave well enough alone and see what happens.
What is done is done if you get my meaning.

It is the original TA engine. Bit of a back story: I bought it in 2011 and started to restore it back to NOS parts as much as possible. Over the years parts had been replaced, as expected. One thing that was wrong were the valve covers. I found the correct covers at Tony's Parts. When I installed them, I discovered that the heads, rocker arms, shafts, and pushrods had been swapped with standard 340 parts. My bad, should have verified that when I bought it. I found all the parts but the pushrods at Chryslers at Carlisle. Later I pulled the engine to detail both the engine compartment and the engine. While the engine was on the stand, I pulled the intake and heads in order to swap the heads and valve train back to the TA parts. I had rags stuffed in the block to protect everything and rotated the engine. When I spun the engine, the towels gave way. The lifers fell out, hence the need for new lifters (dummy me). I had a really hard time verifying the correct pushrods and lifters since the original parts can not be found.
You are right, whats done is done. Since replacing the drive train it only has maybe 100 miles on it. I think I will take the oil filter out and cut it open to see if there is any metal.

 

[Xcudame]

My only concern is the pushrod length. They're about 1/8" longer. The hydraulic lifters can safely adjust for about .080" running. You may have the plunger close to bottoming out now! You've run the engine with the longer pushrods for 100 miles?? What rpm??? How far are the rocker arm adjustment screws sticking out? you want 1 1/2 to 2 threads. Are you at just about no threads below the rocker with the longer push rods?? Pictures might help!

 

[Deezel]

Are you positive on that part number for the Comp lifters? Using that part number, those lifters are for a Ford, not a Mopar. They would fit the bore but very loosely as they have a smaller OD. Comp Magnum Lifters are 867-16 and Comp High Energy Lifters are 822-16 for sets.

 

[DetMatt1]

Hopefully you won’t have any issues with Comp quality or lack there of. I’m sure not everybody does but I have on a couple of occasions and as a result they’re on my personal black list.

 

[rusty409]

Are you positive on that part number for the Comp lifters? Using that part number, those lifters are for a Ford, not a Mopar. They would fit the bore but very loosely as they have a smaller OD. Comp Magnum Lifters are 867-16 and Comp High Energy Lifters are 822-16 for sets.

Good catch. It was a typo. The lifers I used are COMP Cams High Energy Hydraulic Lifters 822-16

 

[rusty409]

Are you positive on that part number for the Comp lifters? Using that part number, those lifters are for a Ford, not a Mopar. They would fit the bore but very loosely as they have a smaller OD. Comp Magnum Lifters are 867-16 and Comp High Energy Lifters are 822-16 for sets.

My only concern is the pushrod length. They're about 1/8" longer. The hydraulic lifters can safely adjust for about .080" running. You may have the plunger close to bottoming out now! You've run the engine with the longer pushrods for 100 miles?? What rpm??? How far are the rocker arm adjustment screws sticking out? you want 1 1/2 to 2 threads. Are you at just about no threads below the rocker with the longer push rods?? Pictures might help!

Figuring out what pushrod to use wasn't easy. Doing research I found a lot of conflicting info on what pushrod to use. The pushrods I used are the ones listed to use on multple websites including Mancini Racing Comp Cams Magnum Pushrods . One piece of info I could not verify is: is the 7.23 pushrod length for a TA engine overall length or effective length (tip to bottom of cup)? The ones I used is overall length.
100 miles is probably high. Onto a trailer, off trailer and cruising at Chryslers at Carlisle, back onto trailer, off trailer. Cruising speed.
When I had the rockers and shafts restored, I changed the adjusters as can be seen on the pics.
If you have a suggestion for another pushrod to use please let me know. I have no problem swapping them out.

 

[Steve340]

If you have pushrods that allow oil up the pushrod to oil the top cup and adjuster I probably would not worry to much.
If not check for signs of heat or galling of the adjuster and the top cup of the pushrod. With a solid pushrod the only oil the adjuster gets is what flicks out of the rocker shaft.

 

[Xcudame]

"One piece of info I could not verify is: is the 7.23 pushrod length for a TA engine overall length or effective length (tip to bottom of cup)? The ones I used is overall length."

Great point! I'll go out on a limb and say the effective length is 7.23". So in that case, your 7.389" pushrods are in the ball park. You should be good to go! Pictures look good!

 

[rusty409]

"One piece of info I could not verify is: is the 7.23 pushrod length for a TA engine overall length or effective length (tip to bottom of cup)? The ones I used is overall length."

Great point! I'll go out on a limb and say the effective length is 7.23". So in that case, your 7.389" pushrods are in the ball park. You should be good to go! Pictures look good!

Thanks for your feedback and reviewing the pics.While I was researching the proper pushrod length, I did assume that 7.23 length was the effective lenght. I am going to check the preload of the lifters again before I start it to make sure the geometry still looks ok. It always helps to get feedback to verify what I did is OK. This stuff can be tricky

 

[GTX JOHN]

I thought 8 of the rockers on the AAR/TA were offset different and NOT
compatible with standard 340 rockers?

 

[rusty409]

I thought 8 of the rockers on the AAR/TA were offset different and NOT
compatible with standard 340 rockers?

the TA rockers are totally different. They are cast vs. stamped and are offset, none of the standard 340 valvetrain is compatible with the TA engine.

 

[Xcudame]

The best way to check the preload is to take one lifter out and make sure all the oil is out (they're easy to dissemble). then you can see how far you're pushing the cup of the lifter in. Best of luck and keep us posted. I'm guessing you'll be OK, but now is the time to check. Blue printing (checking all dimensions) is a very good thing.

Those 340 T/A engines with a bigger than factory cam can be rev'ed to an easy 7000rpm (maybe even 8000 rpm)! The biggest limiting factor of Mopar engines (besides the T/A and hemi) for high revving is the stamped rocker arms. Not that there is anything wrong with the stamped rocker arms below .515" lift and 5800 rpm!

 

[rusty409]

The best way to check the preload is to take one lifter out and make sure all the oil is out (they're easy to dissemble). then you can see how far you're pushing the cup of the lifter in. Best of luck and keep us posted. I'm guessing you'll be OK, but now is the time to check. Blue printing (checking all dimensions) is a very good thing.

Those 340 T/A engines with a bigger than factory cam can be rev'ed to an easy 7000rpm (maybe even 8000 rpm)! The biggest limiting factor of Mopar engines (besides the T/A and hemi) for high revving is the stamped rocker arms. Not that there is anything wrong with the stamped rocker arms below .515" lift and 5800 rpm!

Thanks. I'll let you know the results

 

[Oregon AAR]

Thanks. I'll let you know the results

Following story. With great interest.

 

[Old Mopar]

pushrods are too long - there should be at least 1 thread showing below the rocker arm - look it up - it is in the mopar engine book! preload should be 0.040 to 0.060. One turn of the screw is 0.040.
Btw spinning a stock t/a motor to 7k is a waste of energy...

 

[Mr Cuda]

I believe @ Xcudame 's quote was;
Those 340 T/A engines with a bigger than factory cam can be rev'ed to an easy 7000rpm (maybe even 8000 rpm)! The biggest limiting factor of Mopar engines (besides the T/A and hemi) for high revving is the stamped rocker arms. Not that there is anything wrong with the stamped rocker arms below .515" lift and 5800 rpm!

I concur with ^. I bought my 71 with a 6bbl 340. It had factory inacurate tach, basically worthless, so you didn't even look at it. The car would cut out when revved. It was always cutting out.
Then I remembered that my buddy put in a soft touch rev limiter with the MSD.
I pulled the 6k chip out, and put in the 7k.
Now you could really get into the power band of the larger cam.
I pulled the 6bbl heads and intake off and put on aluminum and a strip dominator.
It did have a lightened bottom end, and could take more, and does now with the 8k chip.