440 valve and manifold gasket difficulties

[vic 75]

Hi Every one. I'm new to these forms. My name is vic. I have owned my 1975 brave D21 440-3 for about 3 years now, and I had afew things that neeeded to be fix on the old girl. My Passenger exhaust manifold was cracked to hell and I picked up a used one on e-bay for $80 CND. and my passenger side valve cover has been leaking for some time, so I picked up a pair of gaskets for another $30. Of course I read all the posts on here about both jobs, and felt ok with both. I broke 1 manifold bolt off On the water inlet bolt, but with my oxy/acs. torch I was able to get it out and the new one installed in an hour or two later. So I thought the worst was over, untill I got to the blody Valve cover gasket. and after reading the post on here about the classic smoke house under the 440. I thought I woud be ok. I soon learned that My very slow leak that I had would be great to try to get them that good again. Holly crap you guys were not kidding. What a pain in he -ss. After trying 3 times with out silicone I decided to put high heat gassket maker on both sides of the gassket and and installed it and let it sit untill tomorrow.I hope that that will do it. I used the coated fibber type of Gasket and only turned the bolts till they were hand tight and a 1/4 turn. But 2 minutes after I stared the engine the smoke started burning. Hope tomorrow will be a better day.
Feb 15 2009 and I'M sure I'm not the only one thats iching to get the old winnie out for a trip. Happy travelling to all.

[Oz]

If all the oil wasn't completely cleaned-off, you'll still be smoking for a while.  You'll still need to re-torque the bolts after a day as well, and after running it the first time up to running temp.  If, after that, you continue to smoke, then you still have a leak. 

[vic 75]

Thanks for the tips. I will try that today when I go back.

Vic 75

[retireddodgeguy2]

Hi Vic,
I share your pain. The older, 70's valve covers love to leak. The book shows only 40 inch pounds of torque when you put them on. That is just about only finger tight. I don't think that is your problem. Over the years someone has really torqued them down and has "dimpled" the holes. Now when you tighten them down, the dimple gets tight and the rest of the cover is loose. When they leak tomorrow, put a straight edge on the inside of the cover and I bet you will find it's warped. I usually give up, and get those new "billet aluminum" or cast chrome covers to replace. I have been able to "flatten" a cover before, but I always use this as an excuse to "dress" up the rig.
Good luck, please let me know if your fix worked, I'm always up for new information.
Mike

[vic 75]

you were right. It still had a small leak, and when I checked the valve covers the holes were down at least an 1/8th. so I give up for now. I guess i will keep an eye out in e-bay or Kijiji for another cover.

[DanielTBolger]

Take a ballpeen hammer and flatten them back.  Take  a .25inch flat bar about 2inch long and a .50inch wide and make a hole down to were the bolt holding the hole plate is that's pushing down.  Don't over-tightening them, that's what could cause the problem in first place .