Idk if this been asked before but what exactly is different in the IPL engine to the normal 3.7 beside the ECU.

 

The engines themselves are identical. It's the ECU and the dual exhaust that make the difference in hp.

 

so i could just buy a IPL ECU and put it on my car and pretty much have IPL numbers or could tuners copy the IPL tune data and just overwrite the data

 

Swapping ECU's is not that easy unfortunately. You'd also need a true dual exhaust. Honestly, you're far better off having your existing car tuned after you install the mods you want via EcuTek.

I found that even with an intake and high flow cats, my air/fuel ratios were in no way optimal (very, very rich in fact) and a tune will not only prevent this but you'll gain quite a bit more hp than just running an IPL ECU.