The best answer to your problem is Pedal extenders. Can you cut the pedals and weld a piece of metal to extend them?
I have changed the angle of Cobra seats with 1/4" thick square washers that we use in construction work. Unistrut, B-Square and Kendrof make them and they are 1 5/8" x 1 5/8" square and have a hole in the center. You can get them with a hole from 1/8" up to I think 3/4". Your local electrical supplier or Lowes will have them. I use longer bolts ( 5/16") and stack the washers till the I get the seat where I want it. I can drive for 2 - 3 hours with little discomfort.
The correct seat height and angle will increase your long term enjoyment of your Cobra.
And I think the correct seat, pedal, steering wheel placement make a Cobra safer to drive. I passed on a offer to drive a 427 side oiler Cobra because the seat / pedals did not fit me. But later got a chance to install an adjustable seat rack in that Cobra and then I drove it.
Dwight