1quickTransAm

iTrader: (4)

I bought the Fel-Pro bottom end gasket kit for my 383 LT1 build, but what are these large and small o-ring type seals for? I don't recall anything like them during the tear down.

LLLosingit

iTrader: (4)

Haven't messed with an LT1 in a while but I think the large go between the block and oil filter adapter. Not sure about the others.

guppymech

iTrader: (7)

The two small o-rings are most likely for the water pump coupling to keep the spline grease in it.

1quickTransAm

iTrader: (4)

I've got an electric WP so good there.

93M6Formula

Yep the small ones are for the waterpump driveshaft. The larger one looks like the seal for the factory oil cooler on 93-95ish LT1s. Goes in between the block and the cooler.

1quickTransAm

iTrader: (4)

I don't have an oil cooler so I am good there too. That does make sense as they are the same size as the oil filter area.

Spartan7

iTrader: (7)

The bigger o-rings look like the ones that come in the oil pan gasket kit. I didn't use them. They might be for the oil cooler.

93M6Formula

Yes because the oil cooler is part of the oil filter setup. In this order.
Block-Gasket-Cooler-Gasket-Oil Filter. But since you don't have one, you just need that paper gasket (the one you show in between the timing cover gasket) that goes behined the oil filter plate and then obviously your oil filter has it's own gasket.

97REaper

iTrader: (11)

I thought those two black o rings were for the opti shaft into the cam?

93M6Formula

Nope, they go on the water pump shaft and the drive shaft. They are there to hold in grease for the splines.