New to engine building-would like some feedback

[Jrm84LX5.0]

Alright I rebuilt the bottom end of my carbed 5.0 in my 84 LX and I've purchased a summit stage 1 intake (supposed to be good from idle to 6000 rpm), equal length 2.5 inch long tube headers with 1 5/8 collectors, a short duration cam with .479 intake lift and .491 exhaust lift, ported some junkyard e7's, and a choice between the stock 600 cfm Holley VS or a 650 Holley DP.

First question is which carb would be better for street/weekend cruiser and

second question is I selected everything (I think) to pull from idle to 5500-6000 or so did I do a decent job or is there anything I should switch?

Third question is how much HP/TQ can I expect and any tips tricks to make it run better timing break in etc?

[iraceitall]

Welcome aboard! I think you have a nice combo there, personally I'd go for the 600 Holley vs the DP. I would guess at the flywheel you are at 290-310hp/340tq, but that's without knowing your compression ratio and piston, and the cam duration (the duration at .050 vs. the advertised). Use a good zinc or ZDDP additive at break in, and my favorite is Rotella 10w30 oil, it's formulated for diesels, so it has the zinc you need to keep the cam from wiping itself out.

[8ballEinstein]

First question is which carb would be better for street/weekend cruiser and

I'd pick the 600 Holley for the better fuel economy.

second question is I selected everything (I think) to pull from idle to 5500-6000 or so did I do a decent job or is there anything I should switch?

It seems you did OK though I'm wondering if the heads are ported enough to run well in the higher RPM.

Third question is how much HP/TQ can I expect and any tips tricks to make it run better timing break in etc?

Tougher question but I'm going to guess 260-270 HP / 310-320 TQ at the flywheel.

[Jrm84LX5.0]

Thanks it will be a great improvement over the stock 170 HP and will ZDDP oil additive and high zinc cam break in lube be enough or should I also get the oil? I'm worried about bog with the 650 but not gas mileage would either of those factors change your advice on the carb?

[8ballEinstein]

Besides better fuel mileage, the 600 Holley is better matched to your engines' breathing capacity. In fact, it could likely support 300 flywheel HP. Even though you can tune the 650 DP to work with your engine, you gain nothing.

(Sorry, I don't have an answer to the oil additive question but I'm thinking you add a quart to your regular oil)

[PIGBOY]

650 bl pump hands down. Never buy the wrong carb and then go buy the right one afterwards, 650 dbl pump is the correct carb for what you have, period. You are at altitude for one. I would even run a victor jr. With that set up for intake. Trust me on this. You need to move air up here and you need the better items described by me to make it happen. 650 650 650

now you have a dilema go with them or stick with me at the head of the pack not looking back.

Now what do we do ?

Either way enjoy.

I have blown cars turbo cars n.o.s. Cars and i do all brands so i have a wee little bit of back ground on this.

I love the you cant run a tunnel above sea level because the carbs are to big. Love it.

Good luck with your baby and let us know how it goes.

[Jerry peachuer]

600 cfm short answer
Look up the word volumetric efficiency
Sounds like you did great so far on your selection good job and keep up the wrenching
5 speed or auto?
What gear ?
The bog can happen on any carb mis adjusted most dp are behind a 5 speed

To not be concerned about mpg is not wise NASCAR is concerned and they are max performance

And at 4.00 gallon 93 octane cruising will be limited unless you own a gas station It adds up 30 bucks for 6 gallons roughly
If you knock down 10 miles a gallon that's 60 miles (12 gallon tank) not far add a couple of fun spirited driving on the e way ramp it's less fuel yet

I'm currently running a holly street avenger 670 vac secondaries 5 speed 331 ci
In a 85 13 miles gallon with a 410 gear not bad but 6 gallons is about 2 hours of street driving mix short blast and bumper bumper
It's tuned spot on and when your not in the throttle it's running on 2 barrels hence vac secondary

Look up mustang fast ford magazine four barrels of fun project car using a 600 cfm and in the mid 12s basically stock 302
Hope I didn't confuse you

Holley.com has a carb selector site very usefull try it out

[Jrm84LX5.0]

Thanks a ton, I used Holley's carb selector, and a desktop dyno and they both said I would only flow 450+/- Cfm so that's why I questioned all the guys telling me I needed a 650 dp although I got it for free from my brother, its a 5 speed and has 3.73 rear diff gears

[Jerry peachuer]

Won't hurt nothing set the calibration to stock and go from there
I normally step up 2 jet sizes from the front to back
Call holly for factory calibration if it's been played with
Jets squirter and cam setting (plastic) colored piece

[Jerry peachuer]

Read the plugs for dialing it in

[Jrm84LX5.0]

Well I got it from my gearhead brother so its been monkeyed with for sure. Thanks for the info and the peace of mind

[Jerry peachuer]

Keep the post going with your feedback and experience with it
Good luck with your build

[Jrm84LX5.0]

I want to say thank you to everyone who posted on this, I went with the 600 vac secondary, I'm getting 14mpg combined, and excellent torque and acceleration (from a little 302), I have to say I'm more than pleased with my setup. I'll be posting Pics soon.