Technical Blown Cadillac Carb Recommedations

Thinking and over-thinking these days about carburation for my 4-71 blown 390 project.
I've run some calculators and am thinking that 850 CFM is around where I'd like to be in total (for max performance). My options right now are multiple original Strombergs (4- 48's probably), Multiple new BIG 97's, dual quads of some vintage type, or one big single honkin' 4bbl.

Here's the basic package:
34 ford cabrio
.030 over 390
Isky 270/280 Mega hydraulic
4-71 blower (10 % OD, for starters)
8:1 Compression Ross pistons
5 speed
3.89 gear 9"

Remember this will be a street car mostly, with occasional trips to the track, and very regular whoopings of @gonzo and @cball sedans.

I can make a 4x2 top plate easy enough, and I think they look the coolest, but not really wanting to spend another $2K on carbs. Also already have a 2x4 plate and the 1x4 plate. What vintage 4 bbls would work well for this? Pros and cons of any of these combinations?
And of course, everyone loves a pic, so...

 

If it were mine I'd go with a couple of AFB's, probably 500 cfm.
Do you have any close up photos of the blower drive? What make is it?

 

I'm actually running a cragar snout now with 2" pulleys. The one in the pic that was mocked up was questionably ID'd as a Pete's Eng or a Montgomery drive, but never got any more info than that. It sure is cool though.

 

I asked about more photos because it looks a bit like a Withers. The Withers was made for SBC's and came with spacers (2 1/2" IIRC) for the water pump and the pulleys and belt were 1 1/2", running between the pump and block.

 

Withers was what I was trying to think of! Not Montgomery. Thanks.

 

I was trying to make that drive fit the Cad, but I don't have the water pump spacers, and the cad pump is just different enough to be a pain in the butt.

 

here's the "Wither's" drive. Would love to have more info.

 

Here you go. BTW how complete is your drive, did it come with the 1 1/2" pulleys or did somebody adapt 2"?

 

FORDORS, what year is that PHR magazine? Very cool info, thanks.

 

Now, back to carburetors, what would I be looking for for WCFBs? Any particular application I should look for?

 

Jim Carter wcfb's came on 55-57 small blocks(power pack singles or dual 4 setups) and similar year caddy singles or dual setups. I think, but I am not positive, the small block singles were 395cfm and duals were 325/each, and the 331/365 caddy version might have been larger cfm.

I can't wait for the regular attempts of whoopings @sproadster30 !!! You know I will put my connecting rods through the side of the block trying..... question is how far will you go after all this work!?

 

Pretty cool car ya have there.

 

There is no date given on the pages and they were cut from the magazine. I would think it was a 1974, or maybe '75 issue.

 

I have not done a lot of blower set-ups, but believe you are thinking too small!

I run two Carter 625 CFM AFB carbs on a normally aspirated 390 Ford in my shop truck. Solid linkage, both carbs run all the time. And it runs great at all RPMS in all gears. Remember, CFM is NOT an additive property in multiple use.

No WCFB's that large.

Like Fordors suggested, I would suggest two genuine Carter 625 CFM AFB's; however the AFB was introduced in 1957.

Rochester introduced the 4G in 1952, and made them in various sizes up through about 1967. They did offer some manual choke 625's.

Just my opinion, but again, have not done a lot of blower set-ups.

Jon.

 

I have two Holley, 600 cfm 1850's on the 6-71 in my coupe and also run direct linkage, never an issue and great mileage on the open road when driven sensibly.
The Weiand 4-71 carb adapter will take the two AFB's in line and I'd follow Jon's advice on the direct linkage.

 

why not just a pair of generic afb 600's? cheap, easy to get, edelbrocks carb manual has the perfect recipe for jets/metering rods/springs. Can't run progressive on a blower app, you need the fuel.
I run a pair of 600's on my blown sbc. air/fuel just a tad rich, which is what you want on a blown setup

 

Carter's and Edelbrock's can be boost referecnced, too, contrary to popular belief.

Mine are. I learned it from @ago

https://www.jalopyjournal.com/forum/threads/boost-referance-edelbrock-afb-carbs.361134/

He ran a 4-hole per carburetor setup. I ran mine with an open design. Either way works.

For a single carburetor, the setup is the same in function.

 

Thanks for the kind words Gimpy. I have over 30,000 miles on this motor now. I haven't touch a thing on the motor other than oil changes

 

This build is definitely going to cost the club a lot of blown up motors and transmissions trying to keep up, Jim's taking things to the next level with this one.