I have dual Delorto 40mm DRLAs on my 2.0 engine with euro P/C's and stock cam and I am wondering of those running carbs, what venturi sizes you are using. I believe the carbs came set up with 34mm venturies. I may have seen a post relating to use a smaller venturi for better driveability. What venturi size do you run and what is your jet set up? If I remember correctly, I may have 140 mains and 60 idle jets. Thanks in advance Dave Hall

34s are perfect for your application. A dell loves a larger vent than a weber.

The combo of jets and vent is perfect for most applications with a Dell if you have a 180 air corrector.

I'd be careful how far you take that though.
I assumed and read pretty much the same thing, but have found the opposite to be true- for drive-ability.
I ran 34's and 30's back to back on the same day in my 1.8L and the 34's resulted in an obvious lag at lower engine speeds and less throttle.
Granted now we're talking a 1.8 ..but for arguments sake.
I tried larger mains and vents together and noticed the smoother top end but it kinda dogged down low.
I think you have to add it's VERY easy to over carb these engines with Dellorto's.
Especially if you don't have the jets/valves to match the airflow thru the carb.
-Bob O

Thanks for the feedback, I do have the 180 air correction jets so, maybe I'll leave well enough alone. Back when I built this thing I purchased a mix of idle and main jets and 2 sets of different venturies and thought with my recent fuel pressure "discovery" it may be time to experiment with tuning. A dyno and exhaust analyzer would be nice to have though….Dave H