Thomas Bailey, 37, and Paul Oliver, 45, carried out surveillance on vehicles delivering cash but were themselves being spied on in a police surveillance operation.
They were arrested after a raid on a Tynemouth pub.
The judge at Newcastle Crown Court sentenced them both to 14 years.
The hearing heard that in January 2014 the pair targeted a post office in Cullercoats but were unsuccessful.
A week later they raided one in North Shields, escaping with Â£9,500 and threatening to "blow the head off" a witness.
In August 2014 they used crowbars to smash their way into the Salutation Inn during an early morning robbery, forcing a woman inside to hand over Â£21,000 from the safe.
Police were by that time bugging their vehicles as the pair spied on security vans, but were not expecting the pub attack.
Oliver, of Watch House Close, North Shields, was found guilty of three counts of conspiracy to burgle, three counts of conspiracy to rob, robbery, possession of a firearm and ammunition.
Bailey, of Falstaff Road, North Shields was found guilty of the same charges.
Det Ch Insp Paul Milner of Northumbria Police said:  "They used extremely sophisticated surveillance equipment to carry out their surveillance of the security drivers.
"They used a fleet of vehicles bearing false number plates they produced themselves from a stolen number plate making machine they had earlier stolen in a burglary.
"However, little did they know whilst they were conducting their surveillance we were conducting our own surveillance on them and were watching their movements."
A third man and two women were sentenced alongside Oliver and Bailey.
Mark Templeton, 46, of North Parade, Whitley Bay, was convicted with robbery at the Salutation Inn and jailed for seven years.
Joanne Oliver, 42, of Verne Road, North Shields was given a 15-month sentence suspended for two years after being found guilty of witness intimidation.
Melissa Bailey, 32, of Penman Place, North Shields, pleaded guilty to assisting an offender and handling a stolen number plate making machine. She was sentenced to 15 months suspended for two years.
Two men who plotted to rob security vans and raided a post office and pub on North Tyneside have been jailed.