That was my boat . sold it to tim. It has been for sale on ebay in mich. I am still amazed that the gill headers survived all this time, i bought them from a hurricane andrew damaged boat.

My 78 CIG 24 Race Boat had a second 24g tank installed forward of the original tank..they also used an electric pump to transfer from the front to the rear tank.

Although I am not sure using the original vent line was the best way to do that, that is how it was done. Pretty simple way to do it I guess. Took me a while to figure out why there was a T fitting in the Vent line about 2 feet down from the original filler/overflow/vent fitting.

Pic of tank removed... not sure what to do with it now.

Is that tank aluminum? Is the fuel sended good? My front tak sender has become flakey.
Looks much like the same installation as both of mine, screwed to the ribs with the welded on brackets and surrounded with spray foam.

No, it is one of the newer cross-linked poly plastic tanks.

This one was just foamed in place...no brackets needed. Heck it took 2 of us over an hour to get it out..sucker wasn't going anywhere.

Sender is good, but senders are not all the same tank to tank, different tank depths etc.

I also have an AFP 77 Gal aluminum tank, it is new and never been used, has sender etc. Was sat into a boat, plumbed and never used as the boat has never been rigged. Not sure what to do with it, came in a virgin hull I "thought" I was going to finish..LOL