Fuel System: Best Edelbrock model recommendations for Studebaker 289 in 64 GT

[jostanton1]

Will a 600cfm Edelbrock carb work well on a 289? Or is it too big? What model do most folks recommend right out of the box? I do not have much experience changing jets and metering rods.

Thanks!

[E. Davis]

I'm running a 1802 Edelbrock 550 cfm on my 289 and so far it works great. Reasonable but not great mileage.

[joncon]

I use a 1403 500cfm on my 63 R1. Runs good. It had a 600cfm on it when I bought it. It runs better with the 500

[Mike Van Veghten]

Been said over and over, the "best" (that word again !) sized carburetor for either a 259 OR the 289 is the "500cfm" version.

While the 600 will work, the low rpm performance and around town mileage...will suffer. How much, depends on your driving style.
The actual cfm that a 289 will use at 5500rpm, at .90% efficient engine (only race engines get this high..!) is...460cfm. That means, a more normal Stude engine, even with a somewhat fresh rebuild will work well with about 350cfm.
Interesting that the Stude engineers chose the WCFB with about that SAME cfm for their standard performance engines..!
So, what this says, that unless you have many performance enhancements, a low rear end gear, and a low first gear in the transmission...the 600 is a waste of time...FOR...the best drive-ability.

There will be many here that will refute this, and that's fine on them. In reality...
I've tested both Edelbrock and Holley carburetors on Stude engines, and from 500 to 650cfm. Guess what ended up on my daily driver Lark...a 500cfm Edelbrock.

As to which version, it really doesn't matter. If you are not a tinkerer, the standard Performer Series, 500cfm, manual or electric choke is the best bet.
If you like to mess around (you say no) the new AVS2-500cfm, manual or electric choke is the best bet.


E. -
Check that, the 1802 is a 500cfm carburetor.
Edelbrock does not make a 550, though I believe Holley does.

Mike

[63looks59]

generally when you order an edelbrock , or when I got mine , it came with lean fuel rods
I think they are shipped that way to be safe , with the supplier not knowing what engine a person may have...
So, for my 289 Hawk ( I have since sold that car) I installed richer fuel rods ( after viewing a edelbrock fuel rod selection chart) and my Hawk ran way better , better than with the rods that came with the carb (it was a carb model 1403)

[bensherb]

I had been running the stock 625 CFM AFB on my GT and it worked fine but I was never happy with it's off idle transition. So I replaced it with the 625 cfm Holley street demon, their version of the thermo quad, it was cheap at $219. It works ok right out of the box, but it's jetted a bit fat so WOT is sluggish. I still need to change the jets. They say it comes jetted to work well on a mild 350 Chevy because that's what 99.9% of them are bought for. If you don't open the secondaries, both of these carbs are only marginally larger than the two barrel carb that came factory on my Lark. In fact all four throttle plate bores on both these carbs are virtually identical to the bores in my stock 4 barrel manifold.

[52-fan]

My brother tried for several years to make a 600 Edelbrock work on his 289. We changed jets and tried everything Edelbrock suggested. He finally replaced it with a 500 and it is much better. My 259 also runs a 500 and I am very satisfied.

[E. Davis]

You are right...my mistake...thanx for fact checking me Mike.

[Xcalibur]

When the Edelbrock AFB first came out, as a single model, I installed several on R-1s and all worked great. However, I don't know recall for certain the cfm on those, but I'd guess it was likely 600. But, I'm sure someone at Edelbrock or a concerted google search would disclose for sure. You'll likely be amazed at how much better a new carb works compared to an ancient and likely worn-out one. All the best!

(btw, all were installed right out of the box, no screwing with the jets)

[Hawklover]

Using a 4103 on my R-1....500cfm

When the Edelbrock AFB first came out, as a single model, I installed several on R-1s and all worked great. However, I don't know recall for certain the cfm on those, but I'd guess it was likely 600. But, I'm sure someone at Edelbrock or a concerted google search would disclose for sure. You'll likely be amazed at how much better a new carb works compared to an ancient and likely worn-out one. All the best!

(btw, all were installed right out of the box, no screwing with the jets)

[StudeRich]

Using a 4103 on my R-1....500cfm

You also might want to recheck that number.

[Hawklover]

You also might want to recheck that number.

Oops.................1403 so sorry;-)

[jostanton1]

I purchased the 1403. I have the older small bore manifold so I'll have to add the adaptor plate. I have heard there are issues with the throttle lever clearing the top of the manifold. What have some of you done to make it clear? Or will I be OK with the increased height I get with the adaptor plate?

[DEEPNHOCK]

I purchased the 1403. I have the older small bore manifold so I'll have to add the adaptor plate. I have heard there are issues with the throttle lever clearing the top of the manifold. What have some of you done to make it clear? Or will I be OK with the increased height I get with the adaptor plate?

The Edelbrock AFB GM A/T kickdown arm will contact the heat crossover passage if left 'as is'.
If you are not running a GM auto trans, all you need to do is trim the lower arm at the stamping fold line (see pic).
Then the carb will fit without any adapter plates.
If you have a stock OE WCFB intake, you will need to open up the secondary bowls slightly to clear the secondary butterfies.
The adapter plate (or the thick Mr. Gasket heat isulator stacked gasket) will buy you that needed clearance, but...
But the 'step' in the secondary throttle bore to intake bore will cause some unwanted turbulence and ultimately affect upper RPM performance.
Best to open up the secondaries slightly, or buy an AFB ready intake from a Stude vendor.

[jostanton1]

Thank-you!