I've searched and read all about this, but I can find the exact answer to these questions:

If I'm using the Felpro positive seals, do I need to put the o-ring in the second groove (intake valves). If not, is there any harm in doing so?

Also, is using the positive seals on the exhaust overkill to the point of doing harm? They seem easy enough to install (engine is out of the car, but heads are on) and they weren't much more costly than the o-rings. The only exhaust seals my parts store had was the o-rings for the exhaust.

Thanks

 

As I have changed the first two intake seals I find there are positive seals on there already. An '88 GTA 305 would not have had positive seals from the factory, correct? I'm changing them anyway as the look like they have been on there a while. I don't know what is under the other valve cover, but would my smoke at start up still be likely with older positive seals, or are they a "never have to worry about it again" fix even if done 12 years ago? The car sat for 6 years before I bought it in '02 and has only gone about 4K miles since then?

Thanks

 

From the factory there were positive seals on the intake valves, but only O-rings on the exhaust valves. If you're using positive seals you don't need the O-rings, but it doesn't hurt to use them.

 

So with the positive seals on the intake valves smoke on startup was still common to our cars? Or was it caused by the o-ring only on the exhaust valve?

 

Smoke is common with aged factory seals due to the material used.

 

Excellent - then this will cure my problem.

Last thing - positives are OK to use on the exhaust valves?

Thanks for the help.

 

I've used positive intake seals on the exhaust valves with no problems.

 

in the old days all we had/used were the positive/umbrella seals . we used them on all the valves . what worked then still works today . they are all cheap enough , why not ? even today when i get heads back from machine shop i again remove springs and install both seals on both valves . works for me , maybe a little overkill but it is cheap enough . good luck .

 

Use the positive seals (Felpro SS72527) on BOTH the intakes and exhausts. I'll bet money your smoke is coming from the exhaust valves. If you re-do the exhausts with the stock-type O-rings and umbrella seals, you'll probably accomplish nothing.
I just did the seals on my '86 LG4 a couple of weeks ago. The intakes looked to be in good shape, but the exhausts were awful - umbrellas flopping loosely on the valve stems. The O-rings, of course, were charred and fell off the stems in pieces. I did NOT use the O-rings that came with the new seals. I see no use in them.

 

Thanks - I have finished the intakes on one side. I was waiting for input regarding the exhausts (I respect the TGO opinions immensely) and have acquired another set of the positive seals for those. I haven't seen any of the exhaust valve seals yet, but I imagine they are shot (I'll get to those tomorrow). I used to get a pretty good puff of smoke when starting a warm car. I'm looking forward to having a smoke free, leak free engine. I'm planning on replacing the oil pan, timing chain cover (and gaskets) and the rear main next.