Howdy Marcus and all:
Hey Marcus- how about some more information from you?
What trans?
What is your use for this car? Is it daily transportation? What about economy? What are you're long range goals for this car and engine?
What is your budget? How much do you plan to do? Are you looking for restoring ideas? resto-rod? Street racer? track only? Are you looking for simple bolt ons, internal mods or both?
Is this a "jig-saw puzzle" project, one piece at a time, or are you going to tackle everthing at once.
I run a Clifford single out header that has been coated by HPC on my modified 250. I chose a single out/single 2" exhaust system because it is lighter, less prone to corrosion and rust, and takes less space in my '65 Rancero. My Ranchero is a daily driver, with ocassional burst of exuberant driving (grin).
I ran a modified cast log manifold with a 2" exhaust system with a DynaMax Turbo muffler and a port divider installed in the head. I switched to the header system at the same time , so it is hard to determine what performance came from which change.
I have a 2300 Holley #4412 two barrel carb mounted directly to a D8xx head. The head and cam, a Comp 260, are performance matched. It is necessary to remove the head to accomplish the modifications necessary to mount a wide base two barrel. This carb is probably not appropriate for your mild application. I have also used several different Autolite two barrels with good success, as well as Autolite #1100 and #1101 one barrel carbs. The Autolite one barrels are compatible with the stock '66 Load-a-Matic distributor. The Autolite 2100 two barrels, are a simplier version of the 2300 Holley, and have annular discharge venturi for a better mix and vacuum signal- a plus for everyday street driving and economy.
Many here have stepped up to a two barrel using a funnel adapter available from several sources, but, the adapter raises the carb an additional 2" and may cause hood clearance issues. I don't believe that a funnel adapter will deliver the same performance as a direct mounted 2 barrel.
The two barrel swap will also necessitate converting to a later distributor,a throttle cable linkage system and a different air cleaner.
I have no personel experience with the Holly/Weber progressice two barrel carbs, but they do make sense for a daily driver and fuel economy. They are less impacted with the use of a funnel adapter.
I am using a recurved DuraSpark II ignition system with an MSD coil. It work very well. I got it, as a unit from the local junk yard, cleaned and modified it and it has run well for about 3 years now. I had switched my stock '65 200 from the 1100 one barrel and the Load-a-Matic distributor to an Autolite 1101 and a '68 point-type distributor with both centrifugal and vacuum advance. That was a nice upgrade- And everything looked stock. It tore up the stock 2.77 non-synchro three speed pretty quickly though.
Now, how about some more info on what you've got, what you've done and what your goals are.
Adios, David