1970 c10 rear gas tank ground clearance

[1970DAVE10]

Unfortunately I purchased a Blazer gas tank from Classictrucks for my C10 long bed. I know there's a company in San Bernadino that makes a screaming conversion tank. I dropped the ball there, but have to work with this one.

I planned on doing a 4 inch drop in the rear, which of course is where this tall bastid is going to go. From the frame rail where the old spare sat, it sits 13 inches from the tip of the rail giving me 11 Inches of ground clearance. With a 4 Inch drop, it will give me 7 inches of clearance. I noticed that my differencial sits the same with 7 inches of clearance. I have some questions for anyone who can help.

1. Have you done this and have pictures from start to finish?

2. Are the 7 inches in the rear ground clearance going to hose me in the long run?

3. Will a 4 inch drop bring down the frame 4 inches, or am I just over thinking it? Never been much into lowering, but in my opinion, that's all you can do to make a long bed look attractive.

Any help is appreciated, and thank you if not.