I would say any 4v ranging from 600-650 cfm should do just fine. Brand would just depend on budget.
https://www.summitracing.com/newsandevents/calcsandtools/cfm-calculator
If the engine is turning over normal, I would think its a fuel or spark issue. When the car will not start is the time to check for both. You may need some help with the process. If its lazy to turn over it could be a timing issue.
Most will come with a plastic grommet you can install in the cover if you want. On my 63 Fairlane I just unscrew the antenna and put the cover on. I removed mine from my mustang and had the hole welded up so I don't remember how the mustangs attach. I like cover craft covers myself, but everyone...
here is a picture of the height difference from the block to the intake. I made an aluminum spacer from the factory gasket and used the gasket on one side and rtv on the other. Have had no issues with it.
TRY HERE
https://www.facebook.com/AFDHEADS/
Some other info from another website
http://www.the351cforum.com/viewtopic.php?f=6&t=568&sid=53a61db5d07e135a7e11a40c5314dfd3
The only thing I completely removed was the drivers seat and the gauges (I have dakota digital) so I could reach from the top, and the emergency brake pedal along with the vent duct on that side (non ac car) as well. Steering column just loosened so it could be moved around some.
AFD will make the combustion chamber to whatever cc you want them to be. When I did the math on mine the compression was to high for what I wanted. Two ways to attack that. One is to use a thicker head gasket set . Cometic and other I'm sure make them. But I chose to have AFD open them up a bit...
What's the old saying? "How fast do you want to go? Well how much money do you have?" LOL unfortunately seems to be a true statement. Mine is still down from the last time we went on the power tour. Bad thing is I have all the parts to put it back together and still have not.
Here you go, just check all your needed boxes and it arrives in the mail................LOL
https://www.moserengineering.com/9-Ford-Auto-Cross-Edition-Full-Float-Rear-End-Package.item
I'm glad you had good luck with carcovers.com because my experience was horrible. Then when the covers didn't fit at all had to pay shipping bac for a refund. never again, if it was free I wouldn't use it because it would advertise for them.