My cross over-balance hose-- what ever you call it is connected to the bottom of the tanks. It is a -12 AN braided hose. It is towards the front of the tanks though because the pump and such are in the way to make a nice loop so there are no up-hill travels. I cannot find any pics of the set up in the boat and it is undercover right now.
T.J.

Gt
 Thanks for the info, My and most efi's do most of that stuff already. Ive been data logging to set my tune witch means My ecu will record all the data of a run or 10 to 20 mins of driving. Then I play it back after words and see how much the ecu is correcting the tune and then I change what is needed like adding or removing fuel to the map, timing, injector pulse width and many other settings. The data logger records the oil pressure, water temp, air temp, elevation, egt,( exhaust gas temp) kpa (percent of load on motor), manifold air pressure, Injector pulse width, timing,voltage, fuel prussure, And many more. what I do is make small changes at a time, make a pass and whether it runs better or worse I change what needs to be. And I save all tunes that run better to a flash drive in case I need to go back for some reason. This is a longer way of tuning but the end result is learning every little thing about efi and will eventually have a perfect tune over time = a  hand full of trips to a local lake. also Learning about it and doing it with my brother is a bonus because we can make changes on the fly at any time instead of paying someone else to tune it, and being stuck if something needs to be changed real quick on the water. I installed a really nice invertor to be able to use a laptop on the water at any giving time. It is hard to tune tho skippin across a lake at 90 mph with a lap top on the bow or lap.I always run the same plugs to end confusion and carry an extra set every where the boat goes. they have to be a non extended reach plug which I found to be hard to find on the river. My pistons will slap the gap shut on normal pulgs witch I found out the hard way in needles which had not 1 plug that would work in the whole  one horse town. Frequent compression checks are a great idea and will add that to my list of things to check and, I also want to run a  inline water pressure gauge even though my boats cooling system couldn't be better. its good to know as much information about your motor as possible for many reasions, mostly for me to go faster

TJs
 I checked my altenater on sat and sure enough it was shot. I dropped it off at auto electric rebuilder's, a great family business with great prices. He said it was a 61 amp and he rebuilding it to 110 amp. So that eliminates one problem. After some serious thinking and drinking and staring at my boat over the weekend And reading some more post Ive decided to go the same route you did.I found some room in the rear sides of the tanks to run a cross over hose.This is going to be a huge pain the the ass since we all know how hard it is to remove the fuel tanks. I think I'm going to go with a -18 or - 20, I figure the bigger the hose the faster it will balance out. I was also thinking to run a t in fitting in the middle to use ig I need to siphon the tanks at the end of the season or some other reason that may present itself. I am Not looking forward to this job I just had these things out. At least if I do it know It will be done before it gets hot and river season. I also need to reseal the whole pump, its been about 7 years since it was sealed last and it leaks pretty bad. If I get these things handled Ill have a turn key race boat ready for the up coming season.

Post some pics of your tank job.
T.J.

more

lots of pics

random

first run

more

the tuner. aka my brother.

Looks good, I guess the balance hose worked.
 How did you pressure test the welds. Also, I hope you guys had no wind when TIG welding outside. Here is how I pressure tested mine.  I made a plastic plug for the filler and then used the vent fitting to add some air to it, about 5psi max, then sprayed soapy water on all the welds and fittings.
T.J.

TJS
My brother is a great welder and always welds outside. He actually built- fabed that whole white sand car in those pics for my dad. that being said I pressure checked the welds after your post and did find a small leak in one of the bungs so thank you for asking me. Its a very minor leak so ill have him fix it tom. I filled the tanks with water and put about 50 to 75  psi more of water from to tanks. I also capped off the tanks and hooked up the balance hose and filled one side with the hose on full blast. it balanced perfect and fast. Then I un capped the tank that draws the most fuel and drained them on the one side to see how low the other tank would empty. It did well. It drained all but about a quarter inch worth. when I pick up the other side a tad and it drained the rest so I think it will will work perfect in the water. I have a few more pics to post of what i just explained Ill post em tonight. I still have a hand full of stuff to do b 4 i re install the fuel tanks but I should have it done by sunday. I'm gonna run 2 vent lines from the tanks to a catch can mounted on the side of the boat next to the sea strainer and put on some sealed or no vented caps. I also need to seal parts of my pump cause its leaking a bit. I'm also going to add a second bung on my exhaust for a second egt. I'm going to buy a digital egt read out for live running to help dial my tune. I wouldn't normally do this but I need it for 3 other projects, 2 sand cars, one with halltec and one with electromotive and a 69 camaro with an excel efi. were swithching them over to E 85.. I'm also going to throw in a new billige pump, mine crapped out on me. I'm also going to install a third battery seperate from the other two strictly for my sterio. I'm doing this so I can listen to my sterio and not run down the battery's that power the starter and msd. basically I can float and completly run the bat down like a few hours and the boat will fire rite up. then recharge at nite. Then install the new alternater. I think that's it. Thank you for your post  TJS.. I always look forward hearing your advice, along with everyone else on this site.

Tis is taking forever

sorry there not really in order but you get the idea.