I'm using '88 block with a one piece rear main seal. Engine is fresh, as is the Felpro rear main seal. But it appears to be leaking pretty badly when the engine is under load. I'm not sure how I could of screwed this up. It's either on, or not.

Anyone have experience with this type of block/seal?

I remember when installing it, it was a rear pain to get over the end of the crank, but once it was on, it almost seemed to loose then. The seal didn't appear to flip or anything either.

Should I use a GM rear main seal instead?

Edit, looking at a pic of the gasket kit I used. What is the large round gasket?

http://www.partsamerica.com/product_images/AAP/FEL/BS40520.jpg

Those rear main seals are pretty much ful proof make sure there is not a burr on the edge of the crank that is cutting the seal and I have seen guys open the seal package with a razor blade and cut the lip of the seal and and have a leak. And there is no groove worn in the crank if there is they make a speedy sleeve to to take care of it.

Mark,
The Fel Pro seal is as good as you will find. You do have to be careful when you tighten the bolts that hold the seal retainer to the block, as the retainer tends to move and can get off center. I always tighten them very lightly and a little on each bolt at a time while watching the retainer to make sure it does not move. I have never seen the second round gasket in your picture, I wonder if it is for the LS1 series engines ? What was the part number on the gasket box ?
You mentioned that the seal was leaking under a load ???? Does it leak just sitting there idleing ? If not, I wonder if you have a problem with crankcase pressure that is forcing the oil past the seal ? What type of breather setup is on the engine ?

Thanks for the replys. I figured it was pretty much full (or is it fool? lol) proof too.

I'm not sure on part number.

I don't think it leaks at idle. I'll have to look further into that though. I do know at under load, it's leaking bad and coating the exhaust sytem and smoking like a banshee.

I'm running a dual breather set up. No PCV. So maybe they're not cutting it.

He're some info, and more of my current problem.

http://www.camaros.net/forums/showthread.php?t=60715