I bought a gas tank insulation kit and it came with two pieces of foam rubber 6" long 2" wide and a half of an inch thick, can anyone tell me where they are installed at? Thanks

Have you dropped the tank yet? I would think they should be installed on top of the tank between the tank and the floor of the trunk to keep the tank from banging or rubbing there.

Yes I have the tank out of the car (69 chevelle) there was nothing in between the tank and trunk floor

Well, to be honest, I have never seen anything between the floor and tank. I have seen rubber between the straps and the tank. Usually the tank is fitting so darn tight - it won't move.

My 70 had three rectangular pieces of 1/2 inch thick foam between the top of the tank and the trunk bottom.

my stock tank had some kind of tar (or oil) impregnated canvas type stuff on top when i dropped it the first time. I just cut strips of this heavy 1/8" rubber mat that we use for workbench tops. worked nice. one fits in the middle of the tank between it and the floor. the other 2 pieces were between the "rails" and the tank where it sits up against the trunk floor.

mine was the same as troposcuba's

My '65 had nothing between the tank & body. I had a 66 that I had to drop the tank on and it had nothing - also. So, based on my experience - I have never seen any pad between the pieces.
That doesn't mean that there were none installed in the cars at one time, but the '65 is a 3rd owner car, I've had it for 20 years and the previous owners were a mother who passed it to a daughter (who sold it because she thought it looked too 'grandmotherish'). But I digress.... I'm confident that the tank had never been off prior to my dropping it - no evidence of a pad.
So, perhaps the early Chevelles did not have the pad and the factory later decided to install them? I don't know...

Since Roger did not say which year he was referring to, I could only offer my experience.

AIM for 69 shows 3 'insulator' pads but doesn't give thickness, size or material. Two are placed on either side towards the front (away from neck). Also shown are two 'anti-squeak' strips on top of the tank running from front to rear. Six inches doesn't hardly seem long enough for the anti-squeak strips.

AIM for 70 very similar.

Mine had 2 rubber blocks on top, about 2 inches wide 6-8 inches long or so.
Definately not factory but they make sweet sanding blocks:D :thumbsup:

Thanks everyone for the help