Pre-requisite information:

75, small block, L88 hood (for plenty of clearance). Rebuild, aluminum heads (don't know exact), pretty aggressive cam. I'm planning on OBX sidemount soon. I will try to get info on everything, but last time I got everything dyno'd I was around 325 HP.

My 750 cfm carb is too big and is boggish off the line. I already have the following parts:

Edelbrock 18054 - Thunder AVS 650 mechanical choke - http://www.amazon.com/gp/product/B00...ms_ohs_product

Edelbrock 8133 - Dual Feed Line with Filter - http://www.amazon.com/gp/product/B00...ls_o00_s00_i01

K&N 16-1330 - Custom Assembly Air Filter - http://www.amazon.com/gp/product/B00...ls_o00_s00_i00 (to show off the carb)

I have a Holley Dominator II intake currently that is spread bore (I believe). The new carb is square bore. I know they make a plate to convert, but what better opportunity than this to buy a new intake manifold!?

So my questions:

1) Would an RPM Air-Gap work with this setup?
2) I have no idea what other fuel lines I need to work with that Dual Feed Line, but I like the idea of a new fuel pump and stainless lines from pump to filter. I believe the dual feed hooks right up to the carb and the filter right up to the dual feed line. My current pump has about 3-4 fitting and is leaking, etc. etc. What pump should I get? What kind of lines do I need? Edelbrock part numbers are fine!
3) What else am I missing here? What gaskets should I be aware of? What other things am I needing? Vacuum lines?

Long story short: I have been a corvetteforum member for over 10 years. I bought my car almost 10 years ago. I have a couple hundred hours worth of work in it. I was 16 when I bought the car. Whether it was lack of time, lack of money, or both, it's never been complete. I now have both. I want to get this thing done and share all my trials and tribulations with this great forum, but I'm needing your help. I'm struggling to wrap my head around everything and appreciate all the help you can offer!

 

With the hood you have, I think the RPM manifold is a good choice and set up with hard lines would be good also. There is plenty of good advice and people willing to help here, good luck in the project.

 

Performance guys are going to tell you to leave the Edelbrock carb alone. A good Holley 650 vacuum secondary should work fine.

 

First of all the 750 is not to big a carb , not to say the carb is not out of whack, all I am saying is dont attribute the bog to carb size .

 

I have a Team G 7530 and Holley 650 Street HP DP under the stock hood of my '76 if you decide to go with that combination or similar. The Team G is a SP manifold but works real well with my setup.

 

Is the trans manual or auto? If auto, you should have a vacuum secondary carb to eliminate the bog.

 

It is an automatic.

 

The current carb is a 750 CFM Mechanical secondary with an auto, which is why I have problems. It is tuned really well for the primaries, but secondaries have always been hit and miss.

I already have the Thunder AVS 650 CFM from Edelbrock and have read nothing but good things about it, both in reviews and from other people that have it. It has a highly adjustable vacuum secondary:

From: http://www.superchevy.com/technical/...ck_carburetor/

"The secondary circuit of a four-barrel carburetor is what can really make the power. When those two extra butterflies open, adding tons of fuel and air to a thirsty engine, a four-barrel carb really roars to life. But tuning four-barrels has been tricky, until now. Most street engines with automatic transmissions behind them don't work that well with big mechanical secondary carbs, (i.e. 750-plus-cfm carbs that have secondary butterflies mechanically linked to the primaries so they open whenever your foot is more than about halfway down on the floor), so we've always recommended running vacuum secondary carbs on the street. Ironically, vacuum secondary carbs don't always produce the best power figures on the dyno, due to the relatively short time we spend at WOT, and so we almost always use mechanical secondary carbs when testing. It gets confusing, we know, but trust us when we tell you that your daily driver will run much better using a vacuum secondary carb.

Thankfully, Edelbrock has taken the guesswork and tuning troubles out of the secondary side of its new carbs by designing an adjustable valve secondary (AVS), which allows you to change the vacuum secondary's opening rate with a quick turn of a screw. Even though the secondary air door is spring loaded, there are no springs to change here. Just loosen one Torqx-head locking screw and turn the adjustment screw to speed up or slow down the secondary's opening rate. It's that easy. The AVS carbs also feature two-step metering rods for independent tuning of the cruise and power circuits."

This carb combined with the RPM Air Gap should work out pretty well, I think. The main question is helping me figure out if I'm grossly misunderstanding something and what else I need to make it all happen.

I appreciate all the responses so far!

 

I vote , do the swap

 

Question:

I'm moving down to a 2 port (inlet/outlet) fuel pump from Edelbrock vs. the standard 3 port stock pump. I've heard different theories on it, but most seem to agree that blocking off the return is not that big of a deal (I have an insulator gasket for my new carb to help with vapor lock). My question is about fitting the inlet line. Right now it is the stock rubber line. My car is at the body shop currently, so can't go look, but how do I convert the inlet line to a stainless or similar line with 3/8" NPT?

Here is the new pump:

http://www.amazon.com/gp/product/B00...=ATVPDKIKX0DER

and here is the line from the pump to the dual inlet feed:

http://www.amazon.com/gp/product/B00...=ATVPDKIKX0DER

All of that makes sense, just trying to figure out the inlet situation.

Also, what is the best way to block off the return line?

 

I just used a rubber cap.

 

Thanks for the response! Can anyone help me with the main fuel line question? Does it usually run a single line from the tank to filter? I imagine it has a connection at some point to move from a steel line to a rubber line. All I know is that it's a rubber line at the filter. I won't be able to see my car for another week or so, so wanted to go ahead and make sure I had what I needed.

 

http://www.lbfun.com/warehouse/tech_...uel%20Line.pdf

 

Great link!