Where can I send my carb for a rebuild?

[team39763]

I know I said I wanted to do things myself so I could learn, but I messed up bad last time I touched this carb.  It's the 750DP that made my truck run like crap.  I know it shouldn't be hard to just rebuild it and tune it myself, but it was a disaster.  Nobody could even tell me what I did wrong either...everybody who saw it said it looked fine.  It leaked around the fuel line inlets, it leaked through the vacuum port, it backfired on hard acceleration, motor ran rich except on WOT, plugs fouled in minutes(sometimes less), motor would spit through the carb.  I really would like to put that 750 back on my truck.  Now that I think about it, it took off harder with the 750(when it wasn't bogging).  I like the 850, but I think I can do better with a smaller carb.  On top of that, the [850's] owner wants $300 for the carb.  I think $300 would go a long way if spent on my 750DP....right?  Anyway, what all would ya'll recommend getting done to the carb?  I'd like one of those HolleyHP mainbodies and maybe some quick-change fuel bowls and 50cc pumps(if needed).  I really don't know what to do with it since I can't seem to set-up a carb correctly and I don't trust any of the locals here.

Truck weighs 3650. 6.0(364), 226 cam,stock heads, victor jr intake, holley 850 w 1 inch 4hole spacer. 3500 converter in a TH350 trans. 4.56 gears w/ 28" slicks. I ran a 12.8@107 at SAR, but it had some problems that are now fixed, so I'm betting 12.5 or better. The 60ft's ranged from 2.0-2.25. I shift at 6800.

[Blue 82]

We need more info on what you have in the 750

what size:
needle and seats
jets front and rear
what size squirters
mech or vacuum secondarys
power valves
best vacuum @ 1000 rpm
what color accellerator pump cams are you running
and at what hole do you have the cam screws in
do you have replaceable air bleeds
clearance on pump arms
accellerator pump(s)

How much fuel pressure
what type of fuel? race gas or pump gas
what diameter fuel line to carb
what style of fuel line to the bowls (please don't say chrome)
Fuel supply info/ pump(s)? filter(s)?

Sounds like you are running rich at idle due to a faulty needle and seat or high float levels
The backfiring through the carb is due to not enough (volume) pump shot or a pump shot that is not long (time) enough.

pics really help

Here's a link you need
http://www.aedperformance.com/Replacement%20Parts.htm

[ccz145a]

$300 would just about get you a new one.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D0%2D80670&N=700+115&autoview=sku

[team39763]

what size:
needle and seats - don't know
jets front and rear - I believe I'm at 68 frt and 76 rr
what size squirters - 28 front and back
mech or vacuum secondarys - mechanical
power valves - 6.5 and plug in rear
best vacuum @ 1000 rpm - I think it was 15
what color accellerator pump cams are you running - stock(pink?)
and at what hole do you have the cam screws in - 1st hole
do you have replaceable air bleeds - I don't think so
clearance on pump arms - very little clearance
accellerator pump(s) - regular

How much fuel pressure - 5-6.5psi
what type of fuel? race gas or pump gas - pump gas
what diameter fuel line to carb - 3/8 with 3/8 return line
what style of fuel line to the bowls (please don't say chrome) - LOL -8AN braided flex line
Fuel supply info/ pump(s)? filter(s)? Mallory 110, transdapt 3/8 inline filter before pump and one before the carb.

I'm headed out right now to put on the 670 avenger.

[Blue 82]

Ok,

I'm sure others will have valuable input....

my suggestion would be to:
Replace the needle and seats with the .110's or .125 vitons
If the front pump cam screw is not at the lowest hole move it there, use the middle hole in the cam. (pink?)
adjust the pump cam arm to push the pump plunger as soon as the butterflies open. Push down on the arms and make sure the pump shots are crisp/clean. Make sure the diaphram return springs are doing thier job. Replace the pump diaphrams if they are not soft.

Install #5531 tube squirters (.031) or the 5535 (.035)
anything over .039 requires the hi-flow screw

remove the plug from the rear power valve
install a 6.5

clean the air bleeds really good
set the floats with the engine off (electric pump- right?)
what altitude are you at?
street driven or track only?

[team39763]

My truck is pretty much track only, it's only on the street when I'm up to no good(not street racing).  I just wish I could get the 750 to perform like the 850 did.  What about "The Carb Shop"?  They say they can tune/upgrade your carb and send it back to ya.
http://www.thecarbshop.com/ourshop.html

[Toolmaster]

Where are you located ?

[team39763]

south Texas

[team39763]

Ok, I found a place to send it.  Are you guys familiar with Chuck Nuytten?  That's who I'm sending my carb to.  He's here in Texas too.  I'll let you guys know how it goes.

[TexasRed]

There's a couple guys in Houston that do good work. Let me know and I can probably put you in touch with a few of them. Although a few of them take a while on their work.

[Pushrod]

Buy a book on holleys. It'll help you tune it ON THE ENGINE YOUR USING better than any carb builder could who hasn't even seen your machine.

If your down with drag racing you better know your carb!!!!!

[SUX2BU99]

My mechanic said he can get me a brand new Holley 600 elec choke for $299, and that's Canadian. Saw one he just put on a car and it looked sharp. I fall victim to most people to have heard about Holleys and are afraid of their tempermental nature. Anything that is extremely adjustable can be like that I guess. He said it would be cheaper to just buy that new carb than try to rebuild or mess around tuning my Edelbrock 1406.

[team39763]

I decided to try to work on it again myself.  I can accept that things don't work, but I have to know why, I can't just accept that it's a bad carb or whatever my neighbors tell me.  I'd really like to learn how to tune my doublepumper.  I bought a holley tuning book, so I'm ordering parts and eliminating other problems - vacuum leaks, plugs, timing.  I'll let ya'll know how it goes.