Recommend a tunnel ram/carb BBC

[F-BIRD'88]

If the vette has a auto trans w/stock converter, 2.73 gears you're going to want to rethnk that..

[Little Mouse]

Would never run that race cross ram on anything like that would make zero differece what carb used. What made the QJ good carb street carb and versital for all things was the two small primaries and its good amount of adjustability. Never been anything exceptional about the afb or edelbrock remake. Both chevy and chrysler threw it away for better designs. I consider the edelbrock dual plane 2 × 4 exactly because i know the cross ram plenuim way to big. If did the edelbrock would almost certainly do two street demons on it.

[Little Mouse]

Never owned an auto in my vettes camaros or anything zero fun to drive.

[MadBill]

Per butt dyno, my cross ram '70 -1/2 Z28 picked up a ton when I switched from 600 vacuum secondaries to 650 DPs.

[Little Mouse]

If i remember right chevy used three carbs on there cross ram. Irst i think was 565 cfm no secondary pump then 600 same way last a 600 dp. If i ever use it i plan on 650 dp. Probably a 406 size engine would tame the thing or mask its faults so to speak with some torque

[MadBill]

Yes, neither pair of the carbs I used were factory parts.

[Little Mouse]

Ive never owned an annular booster carb. But know one person had a demon that the boosters could be changed in. So he took his down leg out installed annular in it and raved about the difference and his was a 427 sbc build. smallest carb in holley style i see with annular boosters is a quick fuel 750 dp.

[F-BIRD'88]

Agree with you on the Edelbrock Dual Quad Rpm dual plane intake.
In fact I bet that if tested A-B on various sbc builds from mild to wild that the intake carb combo will out perform the old cross rams on every build.
It will be better overall in every way. But the crossrams are neat anf can be made to run well with modernization.
We have some tuning tools now that you just did not have back in the day. Ya you can and will want to play with the internal plenum.

[F-BIRD'88]

Now you can own a high perf carb with annular booster at a very affordable price. The Edelbrock AVS2. 500-650-800 cfm.
Great in pairs. Great on crossrams,tunnel rams and Dual Quad Dual Plane Hi- Rise.

[MadBill]

Agree with you on the Edelbrock Dual Quad Rpm dual plane intake.
In fact I bet that if tested A-B on various sbc builds from mild to wild that the intake carb combo will out perform the old cross rams on every build.
It will be better overall in every way. But the crossrams are neat anf can be made to run well with modernization.
We have some tuning tools now that you just did not have back in the day. Ya you can and will want to play with the internal plenum.

DV told me he and Terry Walters spent most of a week on the dyno trying to make good power with an Edelbrock BBC cross ram and that when they gave up and went back to a well-sorted single plane, gained almost 100 HP.
Since I was happy with the (single plenum) factory cross ram on my Z28, I'm now in the process of adding a big connecting channel between the two plenums of my X96, which I can then test open and shut to see for myself.

[F-BIRD'88]

I had to google to see what you are refering to.... Ha ha.
Ya on this manifold it looks like there is no cross joining pipe . on this I'd think to try 2AVS2 carbs mounted sideways like the max wedge cars.
I'd be wanting to cut the top off and make a bolt on removable tops. To allow internal development mods. Different carbs and locations etc etc.
Fun to play with. In my mind these manifolds need 4carbs not 2... Could be 4 2bbls.
Eg:
4Qjets. But using the 6 venturii scheme. (12 venturii total)
This gives much more symetrical venturii configuration.
The (4) secondaries air doors need not open wide open at wot. (4) Small reactive primaries for "drivability".
Located in the center od each plenum...Progressive air door secondaries. Adjustable max flow rate. Tweekable wot throttles blade angles to aid fuel direction/distribution. The 2qjet (6v) carbs can be spread apart and moved around on top of the plenums to see what works best. Remember the front carb of each bank is just a secondary carb. Its primary side is not active/not exposed to the plenum pn each plenum bank.
Ya a connecting pipe should be exammined.
On those old eddy cross rams my first order of business would be modifying the plenums for bolt on removable carb tops.

[Little Mouse]

Nobody can make any of the junk twin plenuim cross ram manifolds work in any form of way makes no difference who you are, there total junk.

[Little Mouse]

The single plenuim on 413/426 wedge worked big time. So did the single plenium hemi cross ram in both its drag race two 4s and its single 4 nascar version. The chevy sbc worked no problem on the race track. All made power easy to tune. All those duel plenium cross rams not tunable and at there best form of tune made no power. Only thing that replaced the single plenuim cross ram was the even better tunnel ram in drag racing.

[F-BIRD'88]

Putting the venturii right directly in front of each intake runner and joining the 2 plenums with a pipe or pipes
Changes how it works. Now the air does not need to make a hard right angle turn from plenum box to intake runners. Shorter direct fuel fliw path. Yet induction pulses tamed by the now connected common plenum which you can now modify cause you cut the tops off to make custom bolt on carb tops. 2x 4 bbls on this style crossram is not ideal. 6v on each with 4 big secondaries right infront of the runners entrance and small center located primarys is a lot better. On each plenum bank. And does not over carb it when you rug it. The air doors of the secondaries ensure this.
Low cost junk yard Qjet carbs. 12 venturii.
95% of carb tuning-jetting is done from the top on manifold with the secondary metering rods and hangers and 4 air door adjustments. Even you could dial it in.
This changes the game on these old Cross ram manifolds. 2x4 holleys are not the only game in town.
Nor the best carbs for these intakes.
The 4xQjet set up can be 12v or can be 16v.

[Little Mouse]

Agree with you on the Edelbrock Dual Quad Rpm dual plane intake.
In fact I bet that if tested A-B on various sbc builds from mild to wild that the intake carb combo will out perform the old cross rams on every build.
It will be better overall in every way. But the crossrams are neat anf can be made to run well with modernization.
We have some tuning tools now that you just did not have back in the day. Ya you can and will want to play with the internal plenum.

Upper rpm power a cross ram will easly out perform a dual plane make far more horsepower. Same as a single plane 4 barrel with easly out horsepower a duel plane 4 barrel manifold. Nascar limits to cfm rated carb even restrictor plates by rules. If not for that tve two four cross ram would be dominate in nascar today. Rules in the way of running it.duel planes are best at lower rpms any form of single plane rules the roost for most horsepower. chevy took its duel plane off and replaced it with the cross ram because there cars were being run at 4500 rpm on up not street driving. The rules in trans am back then anything used on the car had to be available to the public. The cross ram never left the factory assembly line on an engine.