Fluid change on a 6" lifted g29???

[dbmachine]

Ok guys my 09 g29 has a few mods so I figured I would go ahead and give it a full tune up. Before changing the engine oil the oil level was just a hair low from the full mark on the stick. I drained all the oil and let it drip for about an hour. After letting it drip I realized there was more than 1 quart of oil in the catch pan. I added 1 quart of Mobil 1 10w30 and after checking the stick its only half way up the mark.

Ok now on to the rear differential. I opened the top fill plug for the rear end oil fill and oil immediately started gushing out so I put the fill plug back on in a hurry. So I removed the bottom drain plug and let it drop for a good 30min while I was doing some yard work. The manual calls for 1.8 quarts and that's roughly the amount that was in my catch pan. So I began to add the fresh new rear end oil and could only get 1 full quart to go before it started spilling back out of the fill hole. I said to my self something isn't right and it occurred to me of the lift putting the rear end and engine at a downward slope. I jacked the cart up the max my floor jack would go and was able to get another .6 of a quart in the rear end.

Here's my question with the increased angle the jakes lift kit puts on the engine and rear should I add more engine oil than just the 1 quart to get the level on the max fill line or not???