Hemi rear main/426

New 91 chrysler 426 block...installed rear main before installing new motor and leaked ALOT..replaced again with rubber seal and two side pieces of non rubber material and still leaking but not as bad..molnar crank..not knurled.....crank did need alot of weight to balance if that means anything.....anyone suggest a good rear main seal for this application.

Thanks moparts
Thanks in advance to all

Is the aluminum seal retainer new or used? Many used retainers are distorted from having the rope seal pounded into them and won't grip a Neoprene seal correctly.

all new.....rubber seal used...no rope

What brand aluminum seal retainer did you use?

Try a rope seal. That fixed the one in Troy's MP block with aftermarket crank.

Avoid the rope seal. Rope seals were not put into motors in the late 60s and 70s. Rope seals are a band aid and will eventually leak. You need to find out why it's leaking. I spent a year researching rear main seals. lots of urban legends out there; knurling, no knurling, etc.
Mine was leaking because of the retainer bolts were offset by a fraction to one side (defect in manufacturing). Enough offset not to seal around the crank. I shimmed it the exact amount that was needed to center the retainer on the crank. Dry since the rebuild over 1300 miles so far without a drip.

Do the math. Measure everything. Find out if it is leaking from the sides or around the crank. If it's the crank, you need to pull the weak side seal toward the crank. There is a good procedure for this. I wrote something up awhile ago on this.
I pulled my engine apart 4 times. After pulling out the micrometer and snap gauges we found the issue. Rear main seals don't leak because of magic. It's math.

You sure about that?

I've pulled them out of original never apart late 60's early 70's motors.

I guess I'm looking for the "magic" seal as I don't want to pull,tear the engine apart and measure. Glad yours worked. Thanks

ANd for the rope seal...who has one ?

Read here on the rope seal Troy put in his Hemi: https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1102381/1.html

Car quest JV551 Victor Reinz brand EDIT listed for a SB but you'll trim it to fit just like a BB install (not sure why it would not be listed for a BB). comes with a tube of silicone

Rope seals work best with the knurling, such as the OEM cranks.
Neoprene is best on smooth journals like many aftermarket cranks have.

My engine builder said they phased out rope seals by the late 60s and 70s. But I will do some more research on that. I hate to re-write history. ...so I will do some research.

The key here is avoiding the frustration of doing a rear main seal twice or more times is to find the answer to "why" it is leaking. Just replacing it with "something" may lead to frustration down the road.
I honestly would do some detective work. I know it is a pain with the engine in the car.
I'm not sure I would not just change everything and hope also.
But if you can look at the upper seal against the crank it may give you some clues.

I always use a "seasoned" oil seal retainer. Never had a problem. Always used rubber seal.

Here maybe your magic seal:
http://www.fastfishautoparts.com/Performance-Engine-Seals.html

It's a new one piece rear seal. I believe you make one cut in it. You will probable have to fish it up through the block and then the retainer.

Good luck,

I agree! Went to a rope seal on my knurled hemi crank. No issues now. The lip seal leaked like a sieve.