Finally got the car in the air for a fairly comprehensive shot of the tank. It is a tight fit, but MAN...does it work well. Not to mention the entire install was basically free for me (I was able to part out the 96 Caprice I bought for more than I paid for it). I dropped a 255 Walbro pump right in the tank and used the plastic fuel lines from the caprice all the way to the LS1 up front. Everything snapped together with some minor mods.
This install included reshaping the front of the tank so it would clear the pumpkin, changing the strap mounts, cutting a hole in the trunk to clear the top then using the Caprice trunk floor center to make and access panel for service. The caprice sending unit connected direct to my autometer fuel gauge.
This tank holds about 22 gallons. With the LS1 in overdrive on the highway getting low/mid 20's (modified motor) the car has a super long cruising range.