Carb question

[cuda hunter]

So I purchased a proform 70 double pumper and put it on the 400. 
And again, I have dpitus.  Can't get the thing to tune. 7500' elevation. 
No matter what I do I can't get the thing to tune for the street.  I have done this many times now.  Seems I keep thinking the double pumper will work "this time". 
 
  I've had great success using a 3310 holley vacuum secondary in the past. I see that I can buy a new one for about 400 bucks on amazon.  But I'm wondering if there is a better carb that I should buy. 

  400/727.  Just cammed.  I need something that will spin these tires and not flood or stall after a burnout.  Any suggestions?

[HP_Cuda]

You can definitely get the proform to work you just need to account for the thin air up there and lean out the jets.

I'd start with a tear down of the proform and see what jetting it has it in and then start dialing down the jets. Most folks go down one size at a time but depending sometimes I start down 2 jets and see.

Here are proform ones:
https://www.summitracing.com/parts/pro-67226?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-proform-parts&gclid=Cj0KCQjwibDXBRCyARIsAFHp4fr7SJMLae8d2mLsseqMdOxXyPRX2vQsvb4Xb-E1t8aTOzRczab2KFMaAmp4EALw_wcB

[Chryco Psycho]

you have the best carbs make I have used , you can make it work but you have to work through the tuning in the right steps .
The best solution would be EFI hands down .

[1 Wild R/T]

Holley suggests decreasing jet size by one number per 2000' elevation as a good starting point. And they come stock jetted for sea level.... So I'd go 3-4 jet sizes....

However as Chryco mentioned EFI would be a great choice, You want to cruise up to the top of Pike's Peak... Or a trip out to Death Valley.... It will run close to the same.... A carb can't do that....

[Chryco Psycho]

every circuit can be dialed in on the proform , you may need jetting & idle bleeds , often you can leave the jet alone & open the bleed a few sizes & improve response that way for example

[cuda hunter]

This is my first proform.  So I am not familiar with them  aside from them being like a holley.

Are the jets the same as holley? Or do I purchase proform jets?

[cuda hunter]

I have never used EFI on an old car. 

Can someone give me a link for a complete set up so I may consider a purchase. Please.

[cuda hunter]

Thanks @HP_Cuda

[RUNCHARGER]

I've used Fitech but have been seeing some of them have problems. My son has a Holley on his Dodge truck and beats the heck out of it, he also has an MSD on his Cobra and it works great too. I have a hunch that 5 years or more from now the Holley will be the one you will be able to buy parts for. If it can live in this thing it will live on the street. Ah, link didn't work, just search Holley Sniper.

fuel_injection

[1 Wild R/T]

Before you buy those Proform jets read the review & consider buying Holley jets...

This is the EFI system I run...   

http://fitechefi.com/products/30002/

And a fuel tank for use with an internal pump...

http://www.tanksinc.com/index.cfm/page/ptype=results/category_id=146/mode=cat/cat146.htm

You'l still need the pump module

http://www.tanksinc.com/index.cfm/page/ptype=product/product_id=227/mode=prod/prd227.htm

Fuel level sending unit

http://www.tanksinc.com/index.cfm/page/ptype=product/product_id=346/mode=prod/prd346.htm

A fuel filter, by using the LS type filter you don't need to run a full length return so...

http://www.tanksinc.com/index.cfm/page/ptype=product/product_id=425/category_id=-1/mode=prod/prd425.htm

You'll need assorted fittings & personally I put a new fuel line front to back....  So figure a couple hundred more for small parts....

But....After a few hours installing everything  it started right up & runs better & more consistent than it ever had... leave it sit for a month, stone cold, put the key in twist it to the run position, wait a few seconds for the system to cycle & twist it to the start position... Fires right up sits & idles beautifully... Drop it in gear & it still idles.. Step on the gas, no hesitation it goes.... 

I live 90 feet above sea level, I've left my house & driven up over Sonora Pass @ 9600 ft, it loses a little power due to the altitude but nothing like a carburated engine.... 

[cuda hunter]

Sweet. Thanks guys. I will look at those options and try to make a decision. 

The reason I would consider efi is that I deal with -20 degrees all the way up to 95 degrees in the summer.
So I'm leaning that way as I have never done that and reliability sure means a lot up here. 

[71-440]

That FiTech system looks pretty interesting.

[cuda hunter]

I backed my timing down to about 17 from 21.
Lowered the float bowls down to where I can barely see fuel.
adjusted idle speed screws to 1.25 turns out. 

Car runs now.  Doesn't die after letting off the gas.

However it smells of raw fuel BAD.  runs like crap.   Kinda spins the rubber.

I'm going to try changing the jets.   I have several holley jets available in the garage so I'll try that first. 

Thanks @1 Wild R/T  for mentioning the review.   Looks like holley jets will work fine.

[Chryco Psycho]

Have you gone through the tuning guide in the archives , you have to make changes 1 at a time & in the right order ?
Simple things like flooring off idle may not be the best , try snapping it 1/2 way & rolling in with a double pumper .
I am unclear exactly what issue you are having , , they often smell rich with a cam & low vacuum at idle as cylinders are not firing & unburned fuel is being pushed through .
if the floats are set too low it can stumble when you open the throttle & then you are adding pump shot to cover ti wasting fuel with excess pump shot

[BIGSHCLUNK]

THROTTLE PLATE ADJUSTMENT OK?  I'm prolly talking out of turn here but I used to have that "raw gas" smell issue. My plates wereclosed all the way...  Adjusted them,  It's a very small set screw on the bottom right side as I recall. Since proforms "look like" Holley it's prolly in the same spot. Anyway smell was gone and ran better.