Sent you a PM.

Rick,

Was that mine?

Jim

On the topic of fuel tanks - how important is it to be able to remove the fuel tank without removing the body? What brought this up was my thinking of what I would do if the fuel sender died? In its current configuration, my tank will be about 16.1 gallons. If I make it small enough to slide out, I’m dropping to about 14.2 gallons. Not a huge deal, but I would like to know from others what the accessibility of the fuel tank on original and reproduction 289 cars (with the tank behind the seats) is.

On original cars, the fuel tank can be removed from the car for service of the level sender. The rear bulkhead panel is removed and the once unbolted, the tank can be slid forward into the cockpit.
I wouldn't make it so the body has to be removed to replace the sender unless removing the body isn't too big of a deal. I'm sure some replicas are hard and some easier to remove though.
Larry

The other dimension you definitely need to check before you make the hole is where the bootlid rises to when you open it. And - importantly - not just where it sits when the boot is open, but where it has to be lifted to in order to release the sliding boot latch. I've seen a few cars with marks on the bootlid where the skin has kissed the filler cap when closing the boot.

If your car is a replica, the dimensions of an original tank may be misleading as it will depend where and how your tank will mount to the chassis. The inverted 'U' clamps, accessed through the inner rear wing, do not allow much adjustment. And yes, the tank is removed by removing the seats, carefully peeling back the glued trim, drilling out the pop rivets on the forward-facing rear bulkhead for removal and sliding the tank forward into the cockpit.

A tip: the 'U' clamps are accessed through a hole in the aluminium inner rear wing, visible in a lot of the period AC factory black-and-white photos of cars in construction. This hole is closed with a very large rubber plug. I don't know the actual diameter of this hole in originals, but the large floor plug supplied for the (might be 4" diameter? Can't remember) drain hole in a Triumph TR4/4A is close. Get the plug before you make the hole, or you may end up with an open hole!

Hole size
 

Aluminium inner rear wing hole is 3 in. with no rubber

Bernie

Thank you for that. I had forgotten that the rear boot support required extra travel to release the catch. I will take that into consideration.