This is easy, here you have some DBW gas pedals
At the back of the pedal you can find 3 holes (7mm diameter), that's how it bolts to the MK4 chassis. You can not bolt it directly to the MK1/2/3 chassis/firewall because it will be to much to the front and because of the floor shape it won't be moving.
All you have to do is to make a bracket (2mm thick steel) with either 3 holes or 3 6mm thread studs and weld it to the MK1/MK2/MK3 chassis. Before welding anything check the pedal height to make sure it moves in full range and line it up with clutch & brake pedal.
It is only theory but I hope is helps.
One more thing. SWAPing 1.8T or other petrol engine from one MK4 chassis into another MK4 chassis does not require replacing the gas pedal. Tested it on 1.4 & 1.6 MK4 - it works.
You have to replace the pedal if you SWAP TDI into petrol chassis or the other way.
MK5/MK6 pedal is different than MK4 because it looks like this:
but on some cars like Touareg, Q7 etc. you will find MK4 style pedal.
Anyway if you have the pedal which bolts to the floor you don't have to do any kind of bracket.
Simply bolt it to the MK1/2/3 floor :laugh: Drilling is easy. I will post some pictures tomorrow.
Because I just fit MK6 pedal into Corrado