Street/strip 69 Dart, 3350#, Cal Tracs and mono springs, 434" small block, made 703 hp on pump 93 with a 950HP (I know dyno numbers but it's what I have) on a engine dyno, it made 543 hp at the wheels on a chassis dyno with a BLP 1.59" venturi 4150 (1050-1100 according to BLP). So far it's ran 6.40 at almost 109 mph. On a pass last fall the fuel pump went out at about 400', looking at the slip from it's best run if it didn't pick up anying in the back half it would've ran 6.33 looking at the front half numbers from both slips.

4.125" stroke, 4.09" bore, ported Indy 360-1's, flow 330 @ .600", ported Indy intake, 268/271 @ .050", .711/.719" measured at the retainers Comp solid roller, 59° R1 block, 1 7/8" Hedman headers, 727 with 8" converter that flashes 4900, S-60 with 4.10 gears and 3.25 radials.

Honestly this combo has been a disappointment compared to my previous edelbrock headed 408 that ran 6.57 with a 1.38 60' and 104 mph at 3260#. The best 60' with the current combo has been 1.44. It seems I've spent a bunch of money for a little pick up. The converter has been worked on twice for the current combo.

Would it pick up with the intake opened up and a dominator?

Thanks Justin.

Might run a few hundreds quicker than the 4150 carb.
My old W5 Duster was on dyno after i sold it. Made 708
That ran 140 in the quarter and 6 teens to give you an idea.
That matches the dyno figure pretty closely.
3220, 727, s/s springs, 4.30 gear.

Was it a pump gas deal? According to the calculators I'm in the 650 hp range.

I had a VERY similar build to yours and when dynoed it was 20 hp better with the dominator then the 950, but torque was up everywhere. However, if I was to do things over again I would have just put a 1050 4150 on it and been done. The Dom did everything fine but I just found the throttle progression on the secondaries to be like a on/off switch and not quite as friendly on the street.

I was running a (4150 style) braswell 4825 1.48 Venturi 1.75 throttle blade. 439 cube 4” stroke r3 W8 deal. Best pass was a 9.46 with a 1.27 60ft. My “bracket” converter won’t do that, but it’ll 60 1.34 about anywhere and print off 6.13 1/8th mile slips over and over. My slip chaser converter 5800 stall tight. The bracket 6200 stall and is looser. I’m switching over to a 4500 series carb, but all data out the window as I’m also going from a 727 to a 904 and have dropped quite a bit of weight out of the car. Cam is pretty mild as I do have the slowest W8 mill on the planet!

I think your motor is begging for more air and fuel
As far as the intake and using a adapter for the dominator type carb. on your intake now I would try that before buying another intake manifold

IMO, your 1.59 main body has the wrong choice of boosters. BLP put in their modified Holley downlegs, which aren't going to have very good signal or shift recovery. I'm pretty sure a properly tuned 4500 carb would be a noticeable improvement, but so would a 4150 with a better match of booster type and venturi size.

No.

Thanks guys.

When I called BLP and gave them all my information and explained what I was doing with the car they recommended the 1.59" ventura and the down leg boosters so that's what I bought.

Most likely if I go with a Dominator my current intake will be converted to fit it as I don't think there is enough hood clearance for an adapter. When I built this engine Brett Miller gave me a ton of help and tried to convince me to run a Dominator from the beginning. I should learn to listen to people smarter than me, lol.

FWIW...I'd put a dominator on it. The 436" sbc in the Camaro we run liked it. 14:1, cnc'd AFR 23° heads, 3k lb car, glide w/ brake, 5.00 gear 9", ladder bars, etc.
However, it didn't like the bigger 4500 flange manifold. Lost a lot of lowend torque due to the larger plenum volume. Ended up putting the 4150 flange w/ the 4500 adapter on it and ran better. Probably could have loosened up the converter to improve things, but still had the old manifold...so I just put it back on.
Both manifolds were Edelbrock Victors.

My feelings exactly.........you saved me from typing it all out.

That being said, the other question is....... how much quicker does it have to be for you to feel the expense of a new carb was worth it?
And, does that seem like a reasonable gain to get from a carb swap?

Using the moroso chart........ I feel that ET’s reflecting 10% less than the engine dyno numbers should be able to be achieved in decent air with a reasonably well set up car.

Take 10% off 703hp, you’re at 632hp.
632hpm@3350lbs shows 9.93@134.8.

I don’t know if the car has been run in the 1/4 mile, but I’d take advantage of some cool fall air and see how the actual mph compares to the moroso chart.

Btw, wasn’t that cam 263/271?

Dwayne you're probably right on the duration and on the HP too. We all know about dyno numbers, for me it was a tuning tool and the numbers are what we got. The track is giving me the real numbers.

What would you recommend on the boosters?

You're probably right on the $$ spent versus the et gain too. In a dedicated race car it would probably run better, being a street/strip deal it's a compromise.

All the tracks near me are 1/8 so it's never been on the 1/4.

I'm like most gear heads who always want to go faster and look for ways to do it. It's a disease, lol.

You cant be that far from Bowling Green. Thats 1/4 mile. I would want to run it 1/4 mile just to see. You need to get the time off to come to Norwalk next year. Be cool to meet ya.

Not Dwayne, but I think you have only two options if you intend to stay w/ the same main body:

1. Braswell downleg boosters (which, IMO, should have been what was in it in the first place, if BLP insisted on downlegs)

2. Annulars

Photo below shows a Holley Ultra HP 1.60" v w/ BLP .600"-ID 12-hole annulars on the left, and two other carb bodies (a Holley Ultra HP 1.58" v and QFT 1.50" v) that both have Braswells.

BTW, the issue w/ insufficient booster signal can affect both the 60-ft and the overall ET & MPH.

EDIT: I'd expect any booster change, especially if to annulars, could put your tune back to square 1. Not that I wouldn't like to see how it worked out for you, but "less expensive" might not mean "less effort" to get it dialed in.

It’s my opinion that generally an annular discharge booster will have better atomization of the fuel than a downleg booster will.

They also generally get the main circuit activated sooner than a downleg.

For a motor in this cubic inch range, with modest compression, big heads and intake, moderate stall speed and gearing......... I think it would be a tough for a 4150 carb with a 1.590 Venturi and a downleg booster to provide as strong of a hit to the converter, or have as strong a shift recovery as if it had annular boosters instead....... assuming both configurations had been optimized.

There’s ET left in the cam as well....... for a price.
Less spring/lifter life, less muffled friendly, etc.

Street/strip........ otherwise known as compromise/compromise.

I'm betting it will love a well-tuned dominator

Yep