well.. whatever it is... my philosophy of car modding is to bring out the full potential of the factory fitted engine... not that i am anti engine transplants... the reason for using the factory fitted engine are as follow:
1. no JPJ inspection problems - u dun even need to send for any inspection
2. maintain the overall car weight - u get better power to weight ratio as u will experience better handling and better performance even the HP is relatively smaller
3. u know the history of ur engine - less problems with the reliability
4. the initial proper modification cost for hp/torque might be more expensive but u get the reliability out of the money spent.
n here are some reasons not to go for engine transplant:
1. heavier overall car weight which deteriorate the overall handling of the car
2. the stock chassis is not designed for a much more powerful engine resulting chassis crack or bend. Weird noise will occur in time to come.
3. JPJ always like to kacau cars with non-stock engines - even u have endorsement, but still kena kacau.
4. u usually end up with a higher cost than ur expected budget as u are getting old engines. Most ppl do not overhaul or rebuilt the engine from halfcut. WHen problem occurs, be prepared with lotsa cash.
5. a proper modification for more powerful engine would usually be more than just the engine itself, for a proper balance, it would include the following:
a) chassis strengthening with either additional spot welding or foaming the chassis
b) bigger brakes
c) stiffer suspension for the heavier engine
d) heavy duty parts for more power n wear n tear
e) n some other unexpected things
So make sure u got enough money then onli proceed with the engine transplant. Else u might just screw up ur car, n maybe ur life.
In short... modifications done to a car has to be BALANCED between each other... for example the suspension need to be matched with the car overall weight, the brakes has to be matched with the engine power, and engine mods also has to be balance in between different parts. The biggest/stiffest/extreme is not always the best. Just sharing some knowledge from my experience and the ppl around me.