Mark, the answer is yes and no.
If you are in receipt of DLA then it's possible you can claim exemption from the UKBA Financial Requirement of £18600 gross income per year.
But..........Even with that exemption you will still need to prove to UKBA that you have sufficient funds to maintain yourself and your spouse.
In basic principle this means meeting a disposable income equal to the current Income Support level of £111.45 per week of disposable income per couple without children (income after rent/mortgage/council tax (for couple) and any secured loans etc.
You also need to prove adequate accommodation.
So you would need significantly more than £74.60 per week total income
