Senior Tech Team
Join Date: Nov 2001
Location: Denair, Ca. USA
3310 downleg 780 vs 3310-6 straight leg 750
Hey guys, so I recently picked up a 3310 (1968) date replacement carb with downleg boosters, 780 cfm and its in clean shape. Needs gone through but its all there and doesn't appear anything really messed with.
I currently have on the car a 3310-6 modern carb that I added a secondard metering block, and quick change vacuum secondary pod. The combo is in my signature.
Would there be any tangible benefit going with the older style carb with downleg boosters vs straight in the one I have now? Other than being rated a few CFM higher, the carbs are very very similar. The 3310 (1968) has the choke flapper removed which is fine, I never use the choke anyway. Only other difference I really see on it is a hole that looks factory cast on the choke side of the secondaries. On some pictures I've seen online there is a tube that sticks out at an angle. This tube has been removed and the hole has been plugged with RTV. It also has a larger hole on the dead middle of the other side that is threaded, that on my more modern version its cast but a blind hole. It was plugged also.
I can post pictures if necessary, but wanted to see if in any opinions its really worth swapping out to the older style for the extra 30cfm rating, and downleg boosters.
1970 Chevelle - Best time at the WCCG 12.749 @ 108.606, 2.011 60' on street tires!
427 BBC, 215 heads, 2.19/1.88 valves with some port work, 60212 Lunati Hyd Roller, 3310 Holley 750, Performer RPM intake, TH350 with shift kit, 3.55 gears 12 bolt posi, Pypes 3 inch kit, it's alive... again!!!