No way would I be putting that flow killer part on my stuff. Fuel distribution will take a dump there. You don't run around at wide open throttle all the time, start thinking about what happens when throttle blades are open 25% or less and that adapter then looks HORRIBLE. Opening up the base instead of 4 holes addresses that to a point and better and better as the carb base to top of runner increases at least to 2-3 inches. Not thinking here, when carb only open to feed off say transfers (low cruise), one side of the carb is feeding straight air, the other side of butterfly is feeding air/fuel. Main booster venture has not activated yet. You're not allowing any verticle distance for those two streams off each butterfly to fully intermingle. Two cylinders will run richer than the other two. Why many V-8s pick up power from adding a spacer under carb, the spacer allows more turn room at top of runners but also allows better mixing up of the streams.
Can't use a 32/36 with that divider there.
Asking to make the runners longer there is a mistake, they already come far too close to carb base as it is. Why people who port the lower always end up lowering the 'X' center portion; that allows better interfeeding of all ports with each other. You cannot jam a carb base right up against individual ports without suffering pretty big power losses. Why the stock 2.3 carb manifold will not flow any more than the stock 32/36 carb even with every mod done to it you can possibly think of. 38/38 on one of those is a power detune. And thinking earlier in the thread that the D port intake was a problem? We should all have such problems, Edelbrock made millions doing the same thing with their Torker line of intakes. NONE of those match the head ports and all intentional. Some of the mismatches were quite dramatic, enough that they warned you against trying to match them back up, doing so was a massive low end power killer.
You can easily INCREASE plenum and gain low end as long as it is not out of shape size wise. There is a ratio there that all engines pretty much like, a 2 inch tall open base adapter on the EFI lower is not out of that range. I'm betting that simply using the two inch thick open base adapter will be about the same as putting on a 38/38 over a 32/36, or very close. Hood clearance is the problem there.
Look at pic on the left, you can easily see shrouding of a port by how shallow the adapter is. Big no-no there. And I don't care for the middle cross which has no gasket under it, thin enough it could crack from vibration, look at further pics on the website. It may be thin enough to crack as well if you put a 4 hole gasket under it. The squeeze may do it.
Biggest rule of porting for ANY kind of power, low or high end, regardless of how big or small ports are-------------you STRAIGHTEN things out. If you must turn then you figure out how to do it gradually, sharp turns can NEVER be made to flow well, you are defying physics. Anything doing otherwise costs you power. Shallow adapters that force fuel to go down then sideways and then down again are the bane of good power and a hundred manufacturers make them. They get two parts to sell instead of one for the money spent in material. One of Offenhausers' biggest flaws, they made wonky parts that defied physics to throw away big power. Much of their stuff looked cool but actually junk.