Hi Holeydub,
You can use 36 or 40mm drla carbs on a stock cu engine.
The first thing I would buy would be the excellent dellorto tuning book from eurocarb.
The easiest way to buy would be as a complete kit from Jim at Stateside tuning. Its over a year since I've priced carbs but I would be suprised if you could get everything on and working for less than about 500 quid. Its not cheap and there's loads of hassle on the way but the end result is fantastic.
You can get drlas from ebay quite cheaply, it took me three sets to make a good pair though, as they tend to be off old alfas, with seized jets and screws etc. You then need to change jets, emulsion tubes, etc etc.
Getting manifolds short enough to fit was/is a problem, in the end I used Type 4 empi ones with narrow inch and a half air filters from vw speedshop. This setup fits if you cut out the middle supporting bar of your engine lid.
As soon as everything is on, you would do well to go to a rolling road to get the final tweaks spot on, or let a good carb man like Steve at gasure cast his beady eye over them.
I've spent a lot of time playing about with jetting and recently managed 23 mpg on a road trip.
https://club8090.co.uk/forum/viewtopic.php?f=1&t=58135" onclick="window.open(this.href);return false;
A few people have done this conversion on here so theres plenty of advice available.
God luck!
