I guess it depends on your ‘better’ definition..
The F4B is designed for 2500-7000 rpm
The Performer is for idle – 5500
The RPM ( and RPM air gap ) are 1500-6500
The F4B and RPM will raise the carb about 3/4" . I have a RPM air-gap and I have about 3/8" clearance on the front corners of the stock air cleaner with the 1 1/2" K&N filter
I doubt that the performance between the RPM and old F4B is that different…
You shouldn’t have too much trouble finding an F4B for under $200 in good shape..the last 3 on e-bay went for $179, $76 and $107 …! The other thing about the F4B is that it’s not only period correct but was an original option…
If you want to go ‘new’ ,I would recommend the ‘air-gap’ as it isolates the runners from the block which is probably a good thing in a Tiger…
Jim
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