If going from a 2-bbl to a 2-bbl (both 318) then there is no need for an intake change.
If going from a 2-bbl to a 4-bbl, then yes the intake manifold (as well as air cleaner, throttle cable, transmission kickdown linkage and so forth) will be needed.
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All 318’s from 1962 to 1989 all used the same bolt pattern that BBD and Holley 2280/6280 use (except for ‘74 Road Runners which uses the larger 360/383/400 Holley 2-bbl (2210/2245) bolt pattern).
That includes all of the 318 BBD, Stromberg (WW-3), Holley (2209/2280/6280) and ’71 Rochester (GV2) that will fit your existing intake manifold (except for the ’74 Road Runner which I doubt anyone will find one of those), that 318’s used.
Now with that said, many of the older carburetors are not calibrated to use PCV or other things like that,
Note: the difference between Holley 2280 and 6280 is the 6280 is computer feedback (not applicable in your case). The Holley 2209 is an older design and is hard to find.
For decades, the carburetor I recommend most, to install on 318 (2-bbl’s) that works the best (in my opinion) - is one from any ’77 318 which can be Lean Burn/SCC or not, or California Emissions or not.
They seem to be the best year calibration and that works best for almost all year changeovers (that use PCV valve – like yours does).
I even put one on my ’86 5th Ave to replace the Holley 6280 Lean Burn it had on it at the time (years before I bought my ’77 wagon).
Those recommended ’77 318 carburetor model numbers are:
BBD-8093-S 49 state and manual transmission
BBD-8094-S 49 state and automatic transmission
BBD-8096-S California Emissions and automatic transmission
BBD-8126-S High Altitude and automatic transmission
BBD-8135-S (same as BBD-8094-S)
BBD-8145-S (same as BBD-8094-S)
BBD-8170-S Lean Burn/SCC 49 state and automatic transmission
BBD-8171-S Lean Burn/SCC High Altitude and automatic transmission
BBD 8172-S Lean Burn/SCC California and automatic transmission
In all actuality, all 9 model numbers above are the same internally – except for High Altitude, which has a compensator for High Altitude (which works fine/normal everywhere else). Also (except for the High Altitude aspect) all 9 will interchange with each other – providing the idle switch and Throttle Position Sensor/transducer is carried over (if using still using Lean Burn/SCC).
The ironic thing is, is your carburetor is already one of the listed above. The jetting is the same, the base/body and top castings are the same on yours as on a 8094s/8135s/8145s. The only real difference between yours and the 8094s/8135s/8145s is the Throttle Position sensor/Transducer and switch, both of with sends a signal to Lean Burn/SCC computer. One could remove those two items or just leave them in place.
BudW