You're not required to show any level of income and in fact your income or potential income cannot be used to meet the financial requirement. It's your wife who must meet the financial requirement for a spouse visa, not you. There are several ways to meet the financial requirement. One way is through the UK partner's employment. If returning from overseas, she would need to currently be employed in the US for at least 6 months and earning at least £18,600/year. Additionally, she would have to have a job lined up in the UK earning at least that amount and starting within 3 months of her return.
If she's not working then she can return to the UK, get a job earning £18,600/year and after she's been in the job for 6 months you can the apply from the US to join her.
You can use your pension in the amount of £18,600/year but you have to be drawing on your pension for at least 28 days before application.
You can use savings in the amount of £62,500 which has been held for at least 6 months untouched in a readily accessible account.
Read through FM 1.7 to understand the options for meeting the financial requirement:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337420/Annex_FM_1_7_Financial_Requirement.pdfTier 2 General work visas are difficult to qualify for if your job doesn't fall on the shortage occupation list because an employer must prove there is no one who doesn't need to be sponsored for a visa who can do the job.