When i got the engine overhauled i got the head ported and that increased the acceleration of car.
Also as the pistons are bigger than stock and the orignal stock thickness gasket was used so i guess that would have increased the compression ratio a little bit..
Khyber and carby Cultus have better lower end torque due to intake manifold design than 4 cylinder EFI Cultus..
Even i can keep the newer Cultus(celerio) behind till 100km/h easily after that car takes the lead for sure being newer and better technology.