Big Block Carb Question. What are Y'all Running?

[jorgensensc]

Okay guys,
I'm super excited about my latest endeavor, but can't divulge too much info as of now due to my belief that Murphy's Law will happen if I Overindulge before the process is over. Short Story is I am getting a vehicle from a board member Saturday. He made me too good of a deal to pass up. The Better news is that my wife fully supports this move and this vehicle will be her driver shortly after I finish it up (it won't take much). Pics to come after Saturday, along with more info!
The problem:
Said vehicle has a really clean 402 Big Block in it. I am completely ignorant about Big Blocks, etc except that I know they make Gobs of Torque (and I've always wanted one). The vehicle has been sitting for awhile without being started (probably about a year). I was told it will probably need a new carb or a rebuild of the original Q-jet. I'm kind of a simpleton and like the tune-ablilty of an Edelbrock. I do know about the advantages of the Q-jet once tuned effectively will be an extremely dependable Daily Driver Carb. The truck has the original intake, which I am not adverse to changing to an edelbrock intake. I can rebuild a used edelbrock myself easily, not so sure about a q-jet.
The Question:
Should I just have the original q-jet rebuilt? If so how much does that normally cost? How can I truly get it tuned correctly, since I can't find a shop around anymore that
A) Will tune a carb.
B) Has anyone there of any age that actually knows how to tune q-jets.
Or should I get an edelbrock? If so which one should I get? I have t on good word from someone that I trust a lot that a 1406 (600 cfm) will be just fine to run a Big Block. I have also seen edelbrock's website that they suggest the 1411 (750 cfm) for the Big Blocks. If I do the edelbrock carb should I get the edelbrock intake as well? Will the carb work more effectively with the edelbrock intake, or will the stock intake work about the same?

Since this will be the wife's daily driver I am not looking for tons of power. Just reliabilty. I don't need her to call me and say she is stranded, and I don't need her late for work because of difficulty starting in the mornings/afternoons, etc. And I definitely don't need her overheating in the Houston traffic.
With that said I know Big Blocks are Gas Guzzlers (no big suprise) and we are expecting that, however what minor mods can we do to not necessarily improve Hp/performance, but to help with a couple mpg on Big blocks. I know the obvious about engines being air pumps, less restrictive intake/exhaust. But is there anything else with these motors that we can do? Will an edelbrock intake help with the airflow, etc to improve mpg? We are working on a limited (read almost no) Budget for this vehicle initially.

Thanks for the input guys, and sorry for the wordiness of the post. The medicine I take makes me talk alot! And when i have no one to talk to it seems that I Type Alot!!
Can't wait till Saturday when I can post some pics!!
Shawn

[ProStreet68SB]

750 is going to be way to much for a 402, we put a 600cfm holley with vaccum secondaries on it and it absolutely loved it.
http://www.67-72chevytrucks.com/vboa...d.php?t=230964

infact the carb that was rebuilt in that thread was the very one that ended up ontop of the 402

[So.Cal.Super]

Here is a bit of what I have learned / Experienced with Upgrades and help from members here on the board and a few local shops.

Mine is a
72 Big block 402.
750cfm q-jet
T-400
4:10 rears
33" tires
Upgrades
K&N 4" round with K&N air raid top
Pertronix HEI,
Full length Ceramic headers and exhaust
I know the engine was apart for new bearings and rings. I think cam is stock. Previous owner wasn't sure. Stock heads rebuilt.


Bought it with an Edelbrock 600 cfm carb (not a 1406) on it.
The carb did ok except at W.O.T. The engine was starving for fuel. From what I know it was not tuned. Nor did I try to tune it.

Had my Factory Q-jet rebuilt (by a local guy who works from his garage. Race teams from all over the county send him carbs. It’s nice to have a good ol'boy so close.) I told him what I had and what I was upgrading on my engine and he set it up accordingly. (I think I paid $275.00 he doesn't use a rebuilt kit he orders all parts specific for what he wants and better quality. With the gaskets he uses I could run mine on alcohol.)

The 750cfm has no problems with towing or going up a grade under load. The 280cfm primaries make it nice for around town.... If I can keep my right lead foot from pushing that darn pedal to the floor.

On the highway I checked it once but I know my Speedo is off. The 33" tires throw off the truck by about 5mph.

In keeping up with traffic @ 70mph I calculated 7.5mpg I think this is also in part to the Speedo being off (not sure how much this effects this.) and at 70 I have no idea how much the secondary’s open up. (Living in So. Cal there is not many level roads so my foot is always on and off the pedal with the grade changes.)

The carb shop that put on my carb and eliminated the divorced choke for an electric choke also made mention of changing out the intake. The stock 402 intake has small low profile runners, which he compared to his 73 Burb 454 (yeah I know different motors.)

If you go after market intake some companies make direct bolt on intakes for the q-jet or you can opt for a normal intake that you can use the q-jet on now (with adapter) and change to a edelbrock / holley which ever later. For street performance the dual plane is recommended over the single (mainly race only) but I am not sure how much MPG you gain/give for performance.

Just my .02

[jorgensensc]

Originally Posted by ProStreet68SB

750 is going to be way to much for a 402, we put a 600cfm holley with vaccum secondaries on it and it absolutely loved it.
http://www.67-72chevytrucks.com/vboa...d.php?t=230964

infact the carb that was rebuilt in that thread was the very one that ended up ontop of the 402

Sounds like you know your stuff.
I sat on hold for 20 min. to talk to edelbrock tech. The guy was a real jerk and really didn't want to help me much.
He also suggested a 650 carb.
I prefer edelbrock over holley (personal preference), but am having a hard time finding a used 650 edelbrock carb. I did find a used edelbrock 750 locally for 100.00 that I can rebuild. If I bought it and rebuilt it could I meter and jet it to run well without drinking fuel? I know there is a lot to the whole air/fuel ratio. So if it is flowing more air (750cfm as opposed to 650cfm) then I would assume to get it truly tuned correctly I would have to dump more fuel, correct? THus increasing overall fuel consumption. Am I thinking of this in the right way?
Shawn

[LockDoc]

-
I had a local guy rebuild the original Q-Jet on the 454 and It works well for me. TH400 and a 3.07 rear, I averaged 12mpg when I went out to the Midwest meet in Nebraska (525 mi. round trip). I will check it again when we go down to the Midwest Truck Nationals in Kansas City, MO next week.... It's about the same distance.

LockDoc

[steelhorse]

I used to run a 429(yes a Ford)and used a 750 vac secondary that had excelent throttle responce and great power.I did put a towing type cam in it so it was a little better than stock.I would go with a performer air gap and a 750 carb that way if you want to do some upgrades later on the carb isnt already maxed out.

[chip46wis]

750 is too much???? as I recall factory carbs were 750 cfm
I have to tell of a local getting his 468 dynoed---he was told by Holley a 770 was plenty,he ran 440hp at best.At the insistence of a couple of old timers we bolted on a old 850 double pumper-----HP went to 473

[ProStreet68SB]

Originally Posted by chip46wis

750 is too much???? as I recall factory carbs were 750 cfm
I have to tell of a local getting his 468 dynoed---he was told by Holley a 770 was plenty,he ran 440hp at best.At the insistence of a couple of old timers we bolted on a old 850 double pumper-----HP went to 473

carbs probably had different jets in it, my dad just got done building a 463 bbc
http://67-72chevytrucks.com/vboard/s...d.php?t=293356

just by re jetting the 770cfm it gained 45 ponies and the motor while on the dyno only used 670 cfm believe it or not.