I recently installed a CHC gearbox behind a 1Z 1.9 turbo enging 1995 for my mk3 94 3d which results in high rpm=(3000) for low speed=(60mph) in 5th gear. After a lot of research in different forums, I understand that gear ratios in final gears are the cause and that I need another transmission with a low ratio especially in the 5th gear. I was advised to use a CTN/ASD which are very good at launching and at cruising on highway; BUT you know that CHC is a 020 category and CTN/ASD are 02A category which means they are different in terms of built and installation as well as the needed equipment for the conversion.

First, Is it possible that I can replace my CHC(020) with CTN/ASD(02A)?
If yes, what do I need for the conversion and what should I consider?
If no, can I use another 020 gearbox code which is equivalent to CHC/ASD in terms of final ratios?

I would opt for an equivalent option if exists because it gonna save me time and money.

Thanks guys in advance