If you were thinking about trying a 4bbl carburetor and you already have the 600 CFM Holley, you might as well try it to see how well it works.

A 600 CFM Holley consists of 300 CFM primaries and 300 CFM secondaries. Assuming your Holley has vacuum secondaries, you could use sufficiently strong springs in the secondary valve actuator to effectively shut them off. The black spring (38R-684) is the stiffest spring.

My Holley book refers to secondary spring kit 85BP-3185 but this number has be superseded by PN 20-13. The kit's contents are described in the Holley Carburetor Catalog on PDF page 83.

Summit Racing has Holley PN 20-13 listed for US$10.95. You can still use this spring kit if you decide to try the 390 CFM carb later on.

Ok thanks. But just wanted to ask, can I use this http://store.summitracing.com/partdetai ... toview=sku adapter for installing 2 or 4 barrel carb to my 1bbr manifold? Seems to me not but you guys tell me please

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i used to have an adaptor that reduced the small base 2bbl down to the 1bbl manifold. u probly could adapt ur 4bbl down to the one bbl if u had such a piece as i had, but why?
u'd have at least 3 adators stacked who knows how high, and u'd be forcing all the volume of a 4bbl thru the restictive 1bbl port.
not a wise idea.

D~~~!

It looks like you could use Trans-Dapt PN 2087 to mount a square or spread bore 4bbl carb onto a Super Six 2bbl intake manifold.

From earlier posts I've read, I think the guys that tried adapting a 2bbl carb to 1bbl intake manifold were not happy with the results. Trying to make a 4bbl carb work on a 1bbl manifold would be even worse.

Ok, anyway I make adapter plate myself tomorrow and trie. I`ll let you know

Thanks!

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That's the spirit! Why pay somebody else to have all the fun?

I got one little used 2bbr Motorcraft carb what was sitting on 305cid Ford Maverick motor. My friend (owner) told that the CFM shoud be somewhere 400 so it`s worth to trie. I allready made drawings and going to make this adapter plate today

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Ok, the adapter plate is now ready. Hopefully today I can try this 2bbr carb...

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Ok, the carb is now installed and I also tried new set-up. BUT, it not workeing as I want to be. Idle is very lame and if I trie to take idle RPM-s lower than 1400 then motor dies. I trie to tune the carb a little today evening then we see. But can it be possible that IF welding (adapter plate welding) is not good (leaking) that this may cause idle problems?
Also I dont understand whats with timing...right now I set initial up tp 10 to 15 degrees but seems like nothing happened, it still pop to exhaust. Motor respons good but as I told no normal idle.
AND one question more - when we made test drive and tried to hit pedal to metal there were no wheelspin. Is it normal for slant six that it dont have enough power to spin tire on this bus or there is still carb/timing issues?

Thanks
Georg

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Sounds like a bad carb and or a bad vacuum leak. It should idle own to 650 rpm.
You should be able to break the tire loose with no problem once you have the carb tuned and the timing set.
I drove a 73 Dodge van for years.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I hope it`s leak cause this carb worked very well on `76 Ford Maverick (302cid)

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One simple test is to spray carb cleaner on possible problem areas. Spray liquid will slow the vacuum leak for a moment, and idle speed will increase. Some people use propane for this, but I haven't tried it. If you know the carb was good, it is probably a vacuum leak.

Wouldn't this depend more on the rear end ratio and/or tire height/width than the state of tune, or was this already covered and I just missed it? I mean, with a 2.76 rear and a 28" tire, I wouldn't expect any tire slippage...

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vm

They didn't normally put that tall of a ratio (2:76) in vans. Mine was a 3:5 ....some were 4:11 gears. Van's are light in the back like a truck and can break loose very easy. The SL6's torque curve starts right about 1800 to 2000 rpm. You can bust a tire loose with an open diff very easy if it is in tune. My 73 did at the drop of the pedal.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Today I trie to weld this adapter plate again and will see what`s happen. It`s really time to get this bus running...only problems and problems.
Also wanted to ask that is it smart to replace this old contact distributor woth electronic one? If so then I order it right away from my dealer FBO Systems...correct recurved distributor and so on.
Right now there is also unknown coil. How much wrong coil may effect timing?

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