Bad luck with Fel Pro 1 piece pan gasket

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BigPoser

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Anyone had bad luck with these? After installing it twice, I was then told by someone in the shop where I bought it that the one piece pan gaskets don't work well with the older block 350's, only the newer ones. That they will leak badly on the front portion that mates with the harmonic balancer, which mine did.

I was told that only the 4 piece gasket sets work for my year, a 73. So after spending hours changing it out twice, I will now attempt to stop the leaks a 3rd time. Luckily, they will let me take the one piece back for a full refund.
 

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I installed a victor reinz one-piece on my '81 and had no leak problems with it. I don't know why the felpro would leak on an older block. That is odd.
 

theblindchicken

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I believe there are two thicknesses to the pan gaskets. One blue and one gray.

Cant rememeber which is thicker, but I installed a blue one on my 74. A dab of silicon RTV in each of the corners for the bearings and she hasnt leaked a drop since. That was well over a year ago. Maybe a full two-three years now.
 

CSFJ

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If I remember correctly, there were 2 thicknesses used on the front of the pan where it meets the timing cover.
 

BigPoser

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I believe there are two thicknesses to the pan gaskets. One blue and one gray.

Cant rememeber which is thicker, but I installed a blue one on my 74. A dab of silicon RTV in each of the corners for the bearings and she hasnt leaked a drop since. That was well over a year ago. Maybe a full two-three years now.

Mine is the blue one as well. I was actually leaking from the bottom of the front part of the gasket at the lowest point below the balancer. I could actually move the gasket with my finder after it was in place. I also put it into the groove by hand to try to ensure that it didn't get folded or creased. I was told to put some High Tex spray on the ends which I did and it still leaked like mad from the front. Per the instructions, they say to put it on dry which is what I originally did.

Bummed for sure.
 

theblindchicken

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Look to see if you can find the gray gasket.. Should help take up any slack. If not, some aircraft gasket or rtv would help seal it up and hold it in place.
 

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I have tried blue one on 78 block and it leaked in the same area. Try the other one. I have dropped the pan slightly and used rtv to get the leak to mostly stop.
 

bucket

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The instructions say to use no RTV, but that is crap. No matter what kind of gasket, you ALWAYS put a dab of RTV in the corners by the crankshaft.

I've also never had any troubles with the 1-piece gaskets, much more reliable than the old cork/rubber combos.
 

1low4x4

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whoever told you the 1pieces suck are retarded, always use 1 piece and then a dab of rtv in corners
 

JJclark

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What I have found there is two gasket thicknesses. The older blocks used a thinner rubber gasket for the front (1/4 inch ?) and the newer blocks used a thicker rubber gasket (3/8 inch) when talking the four piece. They do not inter change. When ordering the fel-pro you need to get the one made with the thinner front.
 

firebane

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SkinnyG

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Rock Auto calls for OS34510T for my '77 Chevy 350. I've installed it, it fits fine.

OS34509T for a '67 327

OS34500R for a '97 350
 

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That is exactly the problem. I had the 34510 and after comparing it to the 4 piece set, it was much thicker. Oil just poured out there. Got it sealed up now though thankfully. Too bad it took 3 tries to get it right.
 

firebane

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Yeah its unfortunately one of those weird things the SBC blocks have that make a lot of people frustrated and annoyed.
 

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