Thanks for the input...
I had forgotten about needing back pressure in the exhaust
I'm not really interested in hot rodding the car, just want to have a reliable DD with good mileage that I can pass along to my grandson some day.
The car already has 2" exhaust and a small muffler , I put in a pertronix ign and opened up the primary jet in the carburetor.
With the stock cam it starts making power at about 2500 and pulls to about 4500 to 5000 if i push it
The car has a 3.40 rear end and 14" tires so its not a ground pounder off the line and a bit sluggish on hills in 4th so i do need more low end.
I Think ill just keep the stock manifold
Thinking about switching to an early 350 CFM hollly 2 bbl. but have had issues with the power valves in hollys before (lots of 55 fords, falcon sprint, etc)
I also have a pair of really nice SU HIF4 side drafts with all the linkage that should flow about 350 cfm and am thinking about having a manifold built for them
Back in 1980 i had a 2.0 with isky cam, mallory dual point, holly 390 4 bbl, header, 10:1 compression in a 72 capri and it ran really well, just started making good power at about 4000 when the secondaries opened and spun up to 7000 but after about a year the booster venturies kept working loose from the vibration and the power valve kept failing.
At that time I was in so cal and there were a lot of parts there for cheep money for 2.0's
Also had a stock 72 pinto that I bought new in 72 and it had all sorts of carburetion and ign problems
I'm also looking for a block to build as a spare while there are some still available.
Again thanks for the input