After checking out and speaking with two different guys today who have built slanters, and getting the same answers, I thought I would run their words by y'all.

Both guys have run 390 cfm Holleys on Offy manifolds on their slants; one pretty stock and the other with headwork and a mild cam.They have also both run the stock 2bbl carbs, in my case that would be a Carter BBD.
Both guys seem to feel that the 4bbl did nothing to improve performance, even if they improved both high speed drivability ( smoothness) and fuel economy if they keep their foot out of it.

Is this consensus about that here as well?

If that is true it seems a performance two barrel on my stock Super Six manifold might be a good performance choice ( trying to get into the 15s this time out). If so, then I see alot of "dirt track" and IMCA Holley 500 2bbls out there for sale. My questions then become: 1- how does a guy set one up on a stock SS manifold in terms of choke, linkages, etc. 2- What kind of performance can I expect from this with a 440ishX 220 ish @050 cam and the typical head mods?

If you are keeping the engine stock, then the 4 barrel does nothing for you...in fact there is a little bit of performance gain if you go with a Holley 350 cfm carb and adapter (mr.gasket 1937, you will need a lokar kick down cable and a different throttle cable). If you are going down the rabbit hole and going for much more engine the super six manifold is the bottle neck and you will be back at the 4 barrel intake for power and mileage to make best use of the increased compression and mods...Offy is OK for street strip use, but is also restrictive compared to the clifford intake if you are going for a fair amount of performance upgrade....


The 500 is not a good street carb as it has had issues in tuning for daily driving, it can be installed just like the smaller Holley 350, but expect problems to occur and areas of drivability to suffer.

I will tell you this much right now... a Volare/Aspen is a really fat body to try and get into the 15's with a slant six and stock body...I have a 1976 Feather Duster and am 400 lbs lighter than you...I only got into the 16's and streetability by going 10:1 SCR, o/s valves, Erson 280/270 cam, 390 4 barrel, hyperpak for low/mid range torque, dutra duals, with 3.55 gearing and an overdrive to make mileage gains, and distributor recurve....I only got 15's by going 11.67:1 SCR, 600 cfm 4 barrel, fat pak, headers, 10" wide drag radials, OCG 549 cam (high lift for use with the compression), leaded gas, and same recurve (strip the rear seat out of the car...), overdrive and 4.56 rear gears...I use a manual transmission so I'm locked up in all gears with no slippage compared to the A904 on the street (and I have enough torque to now wipe out my clutch every other day of racing)...none of the above builds will smog in PDX.

So if your target is going to be 15's in a 36-3700 lb car...you will be targeting lots of compression, better rear ratio, upgrade the tranny, 4 barrel mandatory, loose some weight out of the car, big cam, Jeffries headwork, larger valves, big cam, headers...

The other guys going that fast or more...use a lighter car (pre-1972 valiant and dart are good)...or, your other option is 'go turbo'...

Just for comparison sake...

I ran a stock body 1973 Duster (about 200-300 lbs heavier than the 1976 Feather Duster) with the 10:1 motor above, 3.55 rear, 3 spd manual, offy intake, single 2 1/4" exhaust, 390 cfm Holley, recurved distributor...that did mid 17's...(exhaust, body weight, and carb size were worth 1 second compared to the previous duster rendition).

Lots of food for thought,

-D.Idiot

Darn good info, my man! You are a fountain of /6 knowledge!
Your first plan is kinda like what I have in mind, except minus the OD ( I have a 904) and possibly adding 100hp bottle shot to it.

Any thoughts on Weber carbs? Cliffy has both single and dual Weber setups. They make claims of +140 HP and torque with cam, Webers, headers and headwork.

So many combos to consider: 2X1, single 4, better 2, webers, etc.

A bolt-on EFI and turbo would be the best for pure performance, but everyone I see running these have to piece them together, fabricate fuel rails, jury rig the electronics, etc. Not into that.

I helped dial in 66Dart's dual non-staged weber setup and just my opinion, it looks neat, but I can dial in a 4 barrel holley faster and for a lot less money than the 2x2 setup...

I have not heard from christopher in a while (luigisir)...if he isn't making headway on his car due to other interests, you might drop him a PM and see if he might want to sell the 10:1 short block I sold him (just build up a head at 46-48 cc chambers with enginbldr valves and springs off ebay and add intake/carb, exhaust, distributor, oil pan, and run it...), it'd be cheaper than the machine shop work for you if he's not done anything. If he bites, you could effectively run it with your super six and a holley 350 to start until you find a craigslist add for an offy or clifford intake, and make the other upgrades to the car (a distributor recurve will be needed, and the engine will want 3.23's).

I would not trust anything clifford has on their site, period...(I barely have added 50-75 ft lbs of torque at the crank to my mill by going extreme on the engine build and using a truck flywheel...)

-D.Idiot