you can reasearch but the Ive seen a few with a VR6
Assuming your 89 Cabrio has a 1.8L (which was most common) if you go to a different engine for more power you are going to run into modifications no matter what, it can range from engine mounts,drive axles to engine wiring harness/ECM. Depending on how good you are at vehicle repairs ect it has been done everyday ppl swapping out for bigger/better power ranging from 1.8L turbo to the VR6 even seen a v8 Cadillac north star engine in a 89golf with or with out turbo. Depending on your budget if it was me I would have the OEM engine rebuilt which can put out as much as 400HP that I know of, some of the VR6's if done right can pump out 700+ HP. Your OEM 8v 1.8L was 105hp where the 16v 1.8 was around 137hp. If you were to swap in a 1.8L turbo from the MK3 years (93-98) they were just under 200hp stock. There are lots of options you could go, if your looking for ppl who have done a major swap (1.8L to a VR6 ect) there is a web site I know of you can check out the pictures and pros and cons which the site is 95% all Volkswagen members. Hope this helps, the site is www.customobsessions.com/index.php its not a spamming site no worries and no fees. If you need more info my profile name is roadrunner in that website I gave you or ask for "jspurr" he has done just about every engine swap you can thing of.
1.8 L 16 valve. Strait swap, more power. More reliable than a VR6,
I hear Porsche motors work great. Its a little more power than you need, but it's an option.....
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