New engine rear seal leaking!

[93project]

Yes, I just got the carb'd 331 running today and it's leaking from the back. I can pull the motor again to change if I have to, I just got through getting in and out of the car 3 times to get it to mate with the T5 so I'm lazy.....
Is it possible that it just needs to swell a bit to seat and seal or is another removal due?

 

[5.0TailPipeHump]

I had the same problem on my new build and ran it for abit , have not had a problem since.

 

[HISSIN50]

Make sure the PCV/crankcase ventilation system is not restrictive.

 

[Mustang5L5]

Mine did the same. Installed it and within 100 miles it would leak to the ground. Now 1000 miles later, it does Not leak anymore. I've done an oil change 100 miles ago so it's full of oil.

 

[Lawbreaker5.0]

^^^^^i think he ment it does NOT leak after 1000 miles. I've heard of rear main seals needing time to sit in and stop leaking. My vert leaks and the coupe doesn't. Only thing I did different was use rtv under the rear main cap.

 

[Mustang5L5]

That's what I meant. No more leaky