Upon leaving school Allen took up an apprenticeship with his father, and quickly stood out for Stratford in age-grade and club rugby as an exceptionally mobile prop forward.
Later that season he was selected for the Rugby News New Zealand Youth Team which toured Germany and Scotland and was coached by Fred Allen and Sid Going.
It was on this tour that Allen picked up the nickname "Bull", coined by Going's nephew Quentin in reference to a character in the American TV Series Night Court then showing on New Zealand television.
He scored two tries in his first match as captain, and two in the semi-final win against Manawatu, finishing the season with 10 tries and a reputation as the most mobile and dynamic prop forward in the country.
To add injury to insult Allen suffered a unique blow when he ripped his pectoral muscle almost completely in a match against Auckland and missed the rest of the season, which saw Taranaki again relegated to the second division.
Allen recovered in time to attend All Black training camps over the summer in preparation for the World Cup, although made the headlines after nearly drowning in a whitewater rafting accident.
The "Bull Fan Club" was appeased when Allen was selected for the All Black tour of Italy and France where he played four games and scored a try against Cote Basque-Landes.
Allen was appointed the inaugural captain of the Wellington Hurricanes team, and led them in New Zealand's first ever professional rugby football match.
The same weekend that the series was sealed, while Allen was in South Africa, Taranaki won the prestigious Ranfurly Shield in a victory over Auckland.