65tripleblack

I've decided to retrofit a 14044836 (LT1/Z28) intake manifold to a 1965 with L76. I need opinions as to which carburetor to mate to this manifold.
The original Z28(302)and the LT1(350) both used a 750CFM Holley with this style manifold. The subject engine will be a well prepared 327, with 30-30 cam, 11.25:1 compression, well ported 461 heads, ported intake and exhaust manifolds, and 2 1/2"-thru Sweet Thunder sidepipes. Close ratio Muncie with 3.70 axle. Con rods will be upgraded to Crower Sportsman's, and I am looking to build 7200-7500 usable revs into this engine.
Car will be used primarily for "street" (cruises, shows, short-to-moderate fair weather trips). It will see duty as a drag racer (ET class-bracket), a few times per season. This car will never see duty in weather below, maybe, 50 degrees. Trying to make it as fast as it can possibly be, while looking "almost" stock, externally. Would be very happy to get into the "high thirteens" with it.
I will almost certainly upgrade from the current 585 CFM Holley, model 2818.
I'm considering a Holley Street HP, model 0-82751 (750cfm). Also looking at Barry Grant models, 5402010GC (750cfm Mighty Demon), 5282010GC (650cfm Mighty Demon), or 1402010DR (750cfm Speed Demon).
Will elimination of a choke horn make very much difference?
I'd rather use mechanical secondaries. What are the points to consider?
Thanks in advance.

Joe

chris ritchie

1. Edelbrock 1406 if you want to bolt it on and have it work correctly right out of the box.

2. Holley if you want to put up with gas leaks and fussy adjustments, most of which you'll screw up and cause the carb to run badly.

3. #1 and #2 will require you to screw around with fuel lines, chokes, and air cleaners. You could buy a rebuilt AFB 3721 and everything would bolt right up. Everything would be stock. If you do this, pay extra for the carb, and get one from a respected rebuilder with a guarantee.

lovevettes

A friend of mine bought a '65 Coupe last year , a L76 ,but it had a Edelbrock carb. on it . He bought a brand new 2818 Holley . Put it on for about 7 weeks , the last time I saw him he mentioned to another friend that he put the Edelbrock back on it , I never noticed that he changed it back , the large stock air cleaner hid it. He also used the stock vacuum advance pipe [ which ran along the valve covers], faked me out. Anyhow he said he changed it back because he got tired of messing with it. I have a AVS Thunder Edelbrock on mine and havent messed with it for 3 1/2 years.

If you decide to go with a Thunder here are some tips.----

The Thunder is unlike the regular Edelbrock carb. It has a spring loaded sheet metal air intake valve at the top of the carb, [to let air in] If your car backfires on wide open throttle when the secondaries kick in [ this is a lean condition ] tighten down on the spring for that flapper to delay the instant air coming in . This will stop the lean condition. Easy fix.

Also if you decide to go with either Edelbrock carb. use the drivers side [ left side] vacuum port for your vacuum advance on your distributor, this is FULL vacuum, it is below the butterfly valves for air intake, the one on the right side [passengers side] is ported vacuum . You cant imagine how many people make this mistake! If you use the ported vacuum there is a very good probabilty that your car will overheat at idle in the summertime waiting for traffic to move.

Jims66

I have an L79 with a 4 speed and .336 rear. 11:1 compression with iron double hump heads with larger valves installed (2.02 etc...). I have the stock '66 L79 alum. intake and a Holley 750 cfm with vacume secondaries which runs fine right out of the box. If I could do it again, I'd probably go with the double pumper. Regarding gas leaks and tuning......, I haven't had to rebuild mine yet and it's been on the car for almost twenty years. The only time I've been into it was to install a reusable (burma) bowl gasket so I can change the jets depending on time of year without tearing the gasket. Although I don't put alot of miles on the car I do drive it year-round in Southern Maryland (from 30s in the winter to high 90s in the summer with lots and lots of humidity !!

JohnZ

The only reason the Z/28 came with a 780 Holley was to make that carb legal for the SCCA Trans-Am engine, and that setup was designed for WOT use between 4000-8000 rpm; for "normal" street use, it's WAY over-carbureted for its displacement. When I was having my 780 restored for my (stock) '69 Z/28, I ran a 600 Holley on it, and it was a much more pleasant car to drive - much crisper throttle response due to the stronger metering signal.

Jims66

When I said if I could do it again I would get a double pumper......, I should have also included the size as well..... a "600-650" double pumper vice the "750" Vacume.