Help me decide which carb to rebuild

[Mudsport96]

So I currently have a Edelbrock 1901 on my very mild 355 right now, and it drives very well except at the top of the rpm range under heavy acceleration. I have my heart set on not digging into it if i don't have too because it no questions asked will fire up every time. Maybe after i rebuild another and don't screw up ill do it.

Anyway, on to the carbs i have acquired.

Had two given to me recently, a 17080205 which seems to be an early 80s truck unit and a 17057229 which i could not find any info on but found a ****7228 which the jets and rods match size wise.

ALL THE APT SCREWS are loose, got very lucky didn't have to heat them or anything
 
Now the numbers:

17057229

DCRs .050
Idle Tubes .030
Upper IAB .070
Lower IAB .063
MAB .050
Idle Bypass .125
Pri. Rods 39B
Jets 64
Secondary Tube Rest. .032
Secondary Rods DG
Hanger J
Fuel Seat .130
Shafts needs bushed

Carb 17080205 Has been Remanned but everything SEEMS to measure OK EXCEPT the Idle Bypass and the primary plates look staked to get them below the transition slots..(i have extras on other carbs)


DCRs .063
Idle Tubes .035
Upper Idle Air Bleed .070
Lower IAB .077
MAB .085
Idle Bypass .039 (Has tin plugs that have been drilled can remove easily)
Sec. Tube Rest. .033
Jets 72
Rods 51M
Hanger H
Sec Rods DR
All the electric choke stuff, choke pull off and linkage is gone as well but no play in throttle shafts

And my 7041200 unit
Dont have all the measurements for this one

Idle tubes .039
DCR .053
Upper MAB .118
Lower MAB .085
Upper IAB .070
Lower IAB .063
Idle Bypass .098

And shafts need bushed

Any unit better than the other for building

Thanks in Advance

Andy


ps engine specs

350 .030 over, comp 268he cam 218@.050 I/E, .488 lift with 1.6 rockers, factory iron intake 346250, 441 heads, about 8.5:1, and hedman block huggers through 2.25 duals. Stock 900 rpm converter and 3.73 gear.

[Frank400]

One  thing I can tell you is that the 7041200 is from an LS-5 1971 Chevelle and is worth good money.

[Mudsport96]

The 7041200 actually came off of a 1971 Caprice with the 365 horse 454. I know because I actually took it off that car in 1997 and put an Edelbrock 1910 on it.
However, I have seen things slip by quality control before and maybe it got stuffed in that car because they were a carb short or something.

[Cliff Ruggles]

The first decision to make is whether to have a divorced choke set-up or electric?.....Cliff

[Mudsport96]

Well the current 1901 runs the divorced and it works good, idles for a minute or two and by the time I hit the first stop light she's off choke. So I could use that on the two others if I went that route, but the 17080205 is an electric choke but missing literally everything on the passenger side of the carb... Choke, pull off all the linkages. As much as the car is actually driven electric isn't that important, and it won't be driven if its below 45-50 degrees anyway. So probably will stick with the divorced choke.

[Cliff Ruggles]

I'd use the 17057229.

[Mudsport96]

Sorry for the delayed response. I like to do my best at reading the entire forum instead of asking too many already answered questions.

I am going to go with the 17057229 as per your suggestion.

As i was reading through the older threads, i came across one particular one from 2011 addressing Single MAB carbs and tuning. It says to tune the SMAB carbs like you would a Edelbrock 1910, but the one you were referring to was a later casting. So would tuning a EARLY SMAB 750 unit be the same, or should i tune for a leaner setup? Or do the smaller primaries even matter that much??

here is the post I took the info from

"M" series rods are also "stepped", it's just not as pronounced as the "K" and "P" series rods.

A 50M metering rod tapers from .050" to .040" on the upper section, then steps to .036"

The "M" series metering rods and made for the later single main airbleed carburetors, as they have a stronger signal to the jets and less emulsion air coming in as the earlier styles with two pairs of main airbleeds.

The SMAB carbs started showing up in 1977, on Chevy trucks, but were still the early divorced choke units.

In 1979 they started showing up on Chevy applications in the later APT style carbs, and were in place across the board around 1980 (side inlet castings only).

When tuning SMAB carbs, refer to the last Chapter in my book on the Edelbrock 1910 units......Cliff

Appreciate the help

Andy

[Cliff Ruggles]

Those carburetors used different metering rods and APT system and tuned in a different manner than the later APT style.

We make an external APT screw for them, and can help with rebuild and tuning parts to get it set up exactly for what you are doing.....Cliff