Hey guys,

My neighbor brought down his 3310-2 for me to go through. It has a rear metering block w/a PV in it. It this right? Didn't think the rear blocks have the PV.

The rear block has 3310-1 stamped on it. Obviously, its from a 3310-1 that used the rear blocks w/a PV. Should be OK to use right? This is going on a hot 400 Pontiac - any jetting suggestions? Has 76's in there.

early 3310s - and many other early Holley perf 4-bbls had a secondary power valve. You can run it with 76s or put in a plug and 84-86 jets. personally, I'd run it and keep the 76s.

Most of the hardest running engines sold by Chevrolet were set up like this. OTOH, if you're into the throttle hard enough to open the secs there isn't going be any noticeable vacuum anyway.

jetting - - run 72/76 with the sec PV. On a 400 inch motor it'll be within a size or so.

Tom, think it will be OK w/the metering block? My concern was that its a metering block from a different type of carb (downleg boosters, etc).

My 3310-3 was very mod'd and rear block had jets but no PV. Unsure if factory or not.