You can get different tension springs for the vacuum pods that will adjust when the secondaries will open.  There is also a set of vacuum pods that have a balance hose between both carbs so that they open equally.

Umm hose between? there are two vacuum lines coming off the base plate of the carbs.  One is a lot smallerthan the other.   Also The carbs came with the chokes removed, and
66 jets
6.5 power valve
.025 acc pump

is this ok to start with for my tunnel ram?  The engine has a mild cam, maybe RV.  .495 lift  299* duration on intake and exhaust ,468ci, 9.76:1 compression, deburred ports, and logs/snails

The large one opens next to the secondaries.

Its not going to give an increase in performance but it will help when it comes time to dial it in (I haven't done it yet, but I plan on it).

Before I put my boat on the water after I bought it I went through the carbs.  Someone had disconnected the secondary diaphrams and installed a small bolt into the linkage making the secondaries come in all the time.  I set them up with stock jetting, new 6.5 power valves and corrected the secondary operation.  So far on a mild 454, low rise dual quad manifold my jetting seems to be very close.

Put them on and run it, once you have it running decent get some plug readings to see if it is over rich (not likely going to be lean).


P.S.  I would have hated to see how much worse my fuel mileage would have been with the locked in secondaries  

SO should I plug the vacuum lines that come off the base?  I have breathers on both valve covers so no need to route lines to the carbs.  Also will a vacuum gague give an accurate reading off these lines or does it need to be off the manifold?  The only way to check one off the manifold is to put a vacuum line plug in the 1 hole that is 1/2 way up the tunnel ram runner on the rear of the manifold...

Sorry for all the questions I will have, but I am determined to be more than a plug and play jet boater.  I want to understand how my equipment works and how to properly tune it.

A vacum gauge anywhere on any of the base lines (except the ported vaccum which will pull 0 at idle) will reflect the entire manifold. For the longest time on one of my tunnel rams, I used an old fogger boss at the end of the runner far from the carb. When I changed it to under the carb, there was no difference.   

The new carbs should have a blow out protection check valve to keep the power valves from being damaged if it does back fire.

Vacuum secondarys are awesome! 
The balance line crewchief mentioned is very important!! it is in the secondary part of the carb in the metering block.

I took my whole tunnel ram to my carb guy , and when I got it back with the carbs rebuilt there was a metal tube connecting my secondaries. I get people asking me all the time how hard it was dialing in my carbs. I never had to dial in shit! They worked great fresh from the shop. The carb guy told me most people have trouble with their tunnel ram due to the carbs not being matched and the vaccuum secondaries not being in sync.

You can either modify the tops of your current vacuum secondary pods or you can get these guys to replace them. http://www.holley.com/20-28.asp

I would think float adj.

Sounds like maybe a stuck float, the last time I adj. a float it seemed backwards from what I thought, I kept turning it the wrong way. Also check your fuel pres. although I'd think all 4 would be gushing if that was the problem.

OK, I fixed it

It LIVES again

The needle and seat assembly is the float adjusting screw.  To adjust float level you loosen the top screw and turn the nut (up/down) which is turning the needle and seat assembly, but if you remove the top screw and continue turning the nut counter clockwise you will remove the complete needle and seat assembly.