Hello Cliff,
Let me first thank you for making some of your knowledge public by publishing your book. You shared ideas, concepts and suggestions that don't appear to have been published before, and we are in your debt. I have purchased your book and read it cover to cover.
I'm sorry to trouble you with this, The combination I'm working with appears to be sufficiently different than any of the published recipes, so if you don't mind, I'd like your suggestions on my best course of action. I know you're terribly busy so I'll do my best to keep this as concise and organized as possible.
Vehicle:'76 Corvette, approx. weight 3450 lbs. with driver
3.55:1 rear gear ratio
TH350 transmission, shift kit & reprogrammed governor, stock converter, shifting at about 5600 RPM.
409 CID SBC, (4.165" bore, 3.75" stroke) 10.5:1 CR,
0.039" quench above forged Probe 16cc dish pistons
Edelbrock Performer RPM (aluminum) cylinder heads
Hydraulic flat tappet camshaft, 0.226 deg./.228 deg. @ .050" lift
Edelbrock Performer AirGap intake manifold, RamAirBox cold air air cleaner assembly
1-5/8" full length headers, 2-1/2" mandrel bent exhaust with X-pipe, Magnaflow mufflers
This is a street car. I will take it to the strip for a few benchmarking/tuning sessions, but the purpose of the car is pure street fun.
I have an Innovate Motorsports LC-1 wideband sensor for tuning.
Carburetors on hand:First of all, I have a small collection of quadrajets for parts, but after decoding them the two that are not e-carbs nor truck carburetors are a 17058504 and a 17057204. The 17057204 has large primaries, however it was commercially rebuilt (has the "T" rebuilder sticker you show in your book) and originally came with #77 primary jets, so unless you suggest different, I'm assuming it is likely not suitable as the air horn and main body are likely mismatched.
The 17058504 came from a friend of mine that bought it from Jet Performance as a Stage II carburetor for his 383 crate engine. He's finishing up an LS1 swap now so the carburetor was sold to me after less than 8,000 miles since the rebuild. It has small primaries and all four main air bleeds are 0.125" ID, however the original jets were #71 with #41 primary rods. I assume it will need some screw-in restrictors at a minimum.
I disassembled it partially (field stripped so-to-speak) to check out what I had. I found that the idle air circuits are drilled but the 1/8" holes in the main body casting have been plugged- but the plugs look commercially done to me.
Here are the measurements I have taken from it:
Idle tube: 0.037"
Idle down channel orifice: 0.052"
Upper idle air bleed: 0.070-0.072"
Lower idle air bleed: 0.081"
Idle bypass air: 0.081", but is plugged in main casting
Holes under idle mixture screws: 0.089-0.092"
If you need any further information, I'm glad to provide it.
Is this carburetor suitable? What recipe would you recommend for it, and what parts will I likely need?
Thanks,
Douglas Staley
