I need to replace the valve seals in my 78 403. Are there different type of seals? Umbrella seals, "o" ring or whatever? My engine sat for several years, now that I have put a couple hundred miles on it I'm seeing smoke when I start it. Im thinking the seals dried out while sitting.

 

If you are going to do it without removing the cylinder heads you only choice is the stock umbrella seals. Just look up whatever part number Fel Pro shows and get them.

 

I used Victor reinz B45418 valve stem seals on my 5.7 diesel.They are the positive type seal with a tiny clamp around the bottom.The clamp expands when you push the seal down over the guide.

 

I might be wrong but I dont think you can put those on the stock 403 heads without machining the valve guides.

 

Another member found a similar positive valve seal and used it on a BBO without machine work. Is the diesel guide the same diameter as the gas V8? My #6 heads had the guides turned down for SBF positive seals, I believe.

 

Thanks for that.To be honest I don’t have any experience with Oldsmobile gas heads.I just figured they would probably work.

 

I did some more looking and it is kind of confusing. Some listings do show a positive type seal but it is for a guide that is .500 od which I dont think the stock Oldsmobile heads are. I think I am going to say the only way to know for sure is take a spring off and measure the guide

 

Thanks Bill, I was hoping you would chime in here. To be honest Im more of a Chevy guy, I spend a lot of time on Team Chevelle.

 

Years ago, I thought a SBF positive seal worked, .530”. I know I’ve had to cut all olds down to .500 before though.