I have what started as an 87 gt. Rebuilt the engine with a 3.1 block from a lumina and used new pistons I believe. The engine is now internally balanced as well. I'm using an 87 timing cover and oil pan.

My question is what is the best way to seal the oil pan? What gaskets to buy? Only black rtv? Or anything else?

It's been a while since I worked on this project. Thanks in advance.

Some gaskets are about same across brand and doesn't matter much.
Felpro w/ Print-o-seal, permadry, and related are made to fix some issues/problems. If Felpro has a gasket w/ those term(s) I get them.

Many gaskets get installed Dry that means w/o any sealer.
Oil Pan sets often need RTV but Only @ joints where sections meet or overlap. Read Directions that come w/ many sets or FSM etc.

RTV only can work but have rules to use. Highlights:
1. Is Clean Everything that the sealer will be applied. Brake clean or alcohol as final step.
2. Do Not get sloppy and use too much. Any that squeeze out you see has done same where you Can't see or clean then boogers can cause problems.
3. If has big gaps to seal then expect will need days or longer to fully cure. "Dry to Touch" is not Cured RTV no matter what label say about cure time.

GM and others use RTV in many parts but often these parts are made for this setup.
Example: SOME Dukes Valve Covers are made for RTV and mod'ed the holes and flange to set right gap for RTV sealer. Early ones use a gasket.
But often they leak from age or repairing problems and Felpro Silicone Set w/ extra hardware and way more expensive is about the only way to install Duke Valve Covers and never leak again.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Thank you very much Ogre.

I used the Fel-Pro Permadry that Ogre mentioned (FEL-PRO OS34501R). No sealer needed, and it comes with four little plastic posts to guide installation. EZ as pie.

quote Originally posted by Notorio: I used the Fel-Pro Permadry that Ogre mentioned (FEL-PRO OS34501R). No sealer needed, and it comes with four little plastic posts to guide installation. EZ as pie.

I tried getting this felpro gasket before but when I received it, I noticed there were these 2 tabs sticking out that made no sense to me because this went right along the mating surface. You can kinda see the tabs in the picture on the right side. Maybe I'm missing something but can anyone explain why that's there or how you're supposed to use the gasket properly?

Contact felpro.

Maybe 2 points helps keep them in place on some engine and others can remove them.

Watch video https://www.youtube.com/watch?v=TX0mx-r319o
This setup may need a little RTV and tells where on some engines.

quote Originally posted by Cunnive: I tried getting this felpro gasket before but when I received it, I noticed there were these 2 tabs sticking out that made no sense to me because this went right along the mating surface. You can kinda see the tabs in the picture on the right side. Maybe I'm missing something but can anyone explain why that's there or how you're supposed to use the gasket properly?

Forgot to mention this was for an 88 and I don't recall those two small tabs being there or me having to remove them, etc. I second Ogre's recommendation: contact Felpro (if there is anyone to talk to.)