Hey Mareo I have had both A14 and A15 engines worked over both engine will rev reliably to 7500 if built properly the A14 would rev to 8000rpm with no real problems. The A15 I had
only had cast pistons 40 thou oversized the A14 had forged pistons 120tho oversized. Even with radical cams had heaps of tourque.The A14 I feel was a better engine as with the
oversixed pistons it had square bore stroke ratio with 12:1 comp it had just over 150hp