With two rounds to go, Howley's side is sitting in second place in the RBS 6 Nations after wins over France and Italy, while Danny Wilson's men are top of the Under 20 Six Nations after three wins out of three.
With preparation crucial in the build-up to Test fixtures, both sides have been working together on the training pitch and have been reaping the rewards according to Howley.
The squads have been able to compete against each other in attack and defence and fine tune their plays in a competitive environment.
"Our Under 20 side have played an integral part of our preparation," said Howley. "We have full contact and unit sessions with them every Tuesday which really puts the pressure on the players and helps both teams.
"Preparation in international rugby is so important, especially when you don't have a lot of time. Having the opportunity to train with and against Danny's (Wilson) side mean the sessions are closer to game intensity.
"It is hard to replicate that level in training but by having two full squads against each other helps us take that step up.
"We are benefiting from it and so are the Under 20s and it's great to see them doing so well.
"They have continued from where they left off in the Junior World Championship last year, winning all their games so far in the Six Nations, and playing some really good rugby too."
Wilson's side kicked off their Championship campaign with a 17-15 victory over Ireland at Parc Eirias and have followed that with victories on the road against France and Italy.
They head to Inverness next Friday for their penultimate game in the Championship against Scotland, before heading home to Colwyn Bay to take on England on Friday 15 March (7.35).
Wales Under 20 captain Ellis Jenkins said: "Training in live situations with the national team has definitely given us a boost. The senior players bring an added intensity and competitive edge to training and set high standards which we've taken onto the pitch in our games."
That preparation will certainly come in handy ahead of the trip to Inverness.
"Scotland have beaten Italy and Ireland and pushed England close so we are going to be doing a lot of work on them over the next week," added Jenkins.
The final Wales Under 20 Six Nations game is at Eirias, Colwyn Bay against England on Friday 15 March (7.35pm).
Over 4000 tickets have already been sold for that game and supporters are being urged to get their tickets early to avoid disappointment.
Wales Under 20 v England ticket info:
Tickets for Wales Under 20 v England are still available from the following outlets:
Colwyn Leisure Centre: 01492 577900 or personal callers (Colwyn Bay Lesuire centre, Eirias Road, Colwyn Bay, LL29 7SP)
Venue Cymru: www.venuecymru.co.uk, 01492 872000 or personal callers (Venue Cymru, Y Promenad, Llandudno, LL30 1BB)
Ticketmaster UK: Telephone - 08442 777 888 or via wru.co.uk/tickets