The Nene was larger, heavier and more powerful than the Heinkel HeS 011 turbojet that had been planned for use in the Ta 183, and therefore required a new, redesigned fuselage with a larger cross-section primarily due to the Nene's centrifugal compressor rather than the HeS 011's axial compressor design. Due to the similarity of the IAe-27a and Tank's redesign of the Ta 183, Juan Ignacio San Martín, the director of the Institute merged the two parallel projects as the "IAe 33 Pulqui II". The fuselage of Tank's design was further adapted to use the IAe-27a's undercarriage. The shoulder-mounted wings were swept back 40°, an even greater sweep angle than that of the Ta 183, and given a small amount of anhedral. Comparable to the Ta 183's engine placement, the Nene engine was situated aft of the cockpit, near the center of gravity with engine maintenance and service facilitated through the removal of the tail section. The airframe featured a graceful, 50° swept-back T-shaped empennage and a pressurized cockpit topped by a clear bubble-type canopy, faired into the dorsal fuselage. Armor was provided around the cockpit and a bulletproof windscreen was incorporated. Fuel capacity was initially 1,250 l (275 Imp. gal.) internally and 800 l (176 Imp. gal.) in the wings. Armament was planned to include four 20 mm cannon, a pair mounted in a staggered, near-ventral position along each side of the fuselage slightly set back from the jet intake. To prove the soundness of the IAe 33 design, two gliders built under contract by another expatriate, Reimar Horten, were constructed and used for aerodynamics testing in 1948–1949, including flights by Tank himself. These tests revealed significant problems with lateral stability, resulting in modifications to the tail to address this problem before construction began on two prototype airframes. Due to the lack of modern machinery, the all-metal fabrication relied heavily on handcrafting, and fabricating the prototypes was a labor-intensive procedure. President Perón envisioned that a benefit of setting up an aviation factory in Argentina would be to introduce production standards comparable to world-class manufacturing facilities. However, Tank realized that production tools and jigs were not feasible at this stage and relied instead on essentially hand-built examples. The first airframe (No. 01) reserved for static testing, was subsequently destroyed during the tests.