This is gonna be lengthy so try to bear with me.
The Lincoln carbs are larger so they may not be suitable on most 2X4 applications except in a full race application. As the original 2X4 carbs are scarce and then expensive when you do find them, use a matched pair of Holley 4000’s (Teapots). The 1161’s or 1162’s seem to be plentiful so these seem to be the carb of choice for 2X4 retrofits. Another option is a pair of 500cfm Carters with adapters.
If going with the teapots, you’ll need to buy two Holley spring kits for the model 4150/4160 carbs and use the yellow springs from those kits in the teapots so that the secondaries actuate at the proper rpms. The factory springs in the single 4V appliation teapots will be too stiff in a 2X4 application for the secondaries to even start opening except at the extreme high end of your rpm range. This is simply because the vacuum signal to each carb is cut in half when using two of them together. The yellow spring is essentially half the tension of the factory silver spring and corrects this. Tapping both of the secondary diaphragm covers for a 1/8” NPT thread and using a hose fitting in each so both secondary diaphragms are hooked together with a length of small diameter vacuum hose will also insure that the secondaries are working in unison. Be sure to install new secondary diaphragms in both carbs when you are kitting them.
Tying two or three of the power valve springs together in each teapot carb is also recommended for the same ‘vacuum signal is cut in half’ reasons. A staple works well for this. The factory 2X4 powervalves for the teapots haven’t been available for some time now which is the reason for modifying the powervalves that come in your kits. Those power valves are designed for a single quad application.
Use a ’57 and up distributor regardless of the carbs being used. For the teapots, unless you modify the carbs for a ported vacuum signal only, then don’t use the vacuum advance on the distributor. I’ve an article planned for an upcoming YBM issue on how to modify the teapot Holley to eliminate the venturi feed for the distributor and make it a ported signal only. In its factory supplied state, the ’56 and earlier teapots have both a venturi feed and ported signal in conjunction with the spark valve to correctly operate the Load-O-Matic distributors. That will not work with the ’57 and up vacuum chamber and provide the correct ignition curve. But easy enough to fix by modifying the carbs if you want to run the vacuum advance along with the mechanical advance for cruise situations. If you’re just concerned about straight line performance, then don’t bother with the vacuum advance portion.
That’s the short answer.
Lorena, Texas (South of Waco)