The wimpiest of the wimps Edelbrock's SP2P

[thigh19]

The SP2P was ment to run with stock single exhaust manifolds. A tork builder. Most people make the mistake of adding a hi-flow exhaust system which defeats the purpose. I'll take tork over horsepower any time, but I like the slow go!

[tufcj]

I got one of the Holley Dominators at the local U-pull-it for $17.99. I lifted the hood of an old Wagoneer, It was so greasy I couldn't see what it was, but could tell it wasn't factory, Scratched some grease away with a screwdriver and could see aluminum, so I took it off (had a factory Motorcraft 4bbl on it). Brought it home and hit it with the Hotsy before I could read the words Holley or Dominator on it. After I read up on it, I found it's worth about what I paid. Sits on the garage shelf for a conversation piece with my other AMC buds.

[79cj7duner]

Had one of these on my 304 and didn't even know it was a POS!!! All I knew at the time was it was a four barrel, and aluminum, and realtively cheap from Ebay! Soooo...I bought a performer on ebay. The thing of it is, the motor runs pretty good with this manifold!! And I have dual flomasters w/ 2 1/4 in. pipe. Still running exhaust manifolds though. Gonna do the Edelbrock headers when I get the money (no exhaust mods- which is a good thing cuz I already spent $400 on my custom flowmasters-complete system w/no cats)

[fulsizjeep]

So...after reading this, I am curious. I am running an SP2P on a 401 bored .030, Comp 260H, AFB 750 with stock exhaust manifolds from the original 360 into single 2.5" exhaust with only a glasspack. I found that if I feather the manual choke down a bit, the power comes up at highway speeds around 65. No tach, this is a 88 Gr Wag with 3.73 gears and 32" tires, estimated 2600 rpm at 65.

You think I am running too lean with these small ports? It feels like it ain't breathin good enough. I have been wondering if I need to open up the bottom. Got a set of Hedmann headers to install and plan to change to duals.

Some people say the SP2P is great for the low end torque for off road use with 360 and 401. Some say ditch the SP2P for a Performer. Opinion?

Thanks!

[79cj7duner]

Definitely find a performer if you have a 304. Really woke mine up. You can actually feel the secondaries open up now, and that is a wonderful thing =D>

No bottom end loss, total gain everywhere with my combo, and I don't even know how big/small/calibration my carb is! How do you tell how many CFM on a Carter AFB?

[fulsizjeep]

Thanks for the feedback. The more I look around, it sounds like the SP2P is a real mistake for a 401.

I found a document on the web that helped me figure out my 750...

To determine Carter AFB carb flow, measure the butterfly bores and use the table below:

CFM Venturi Diameter Bore Diameter
primary secondary primary secondary
--------------------------------------------------------
400 1 1/8 1 1/4 1 7/16 1 7/16
500 1 3/16 1 1/4 1 7/16 1 11/16
575 1 1/4 1 9/16 1 9/16 1 11/16
625 1 3/16 1 9/16 1 7/16 1 11/16
750 1 7/16 1 9/16 1 11/16 1 11/16

9000 Series AFB Code Deciphering:
Base part number is 9000 and the last three digits refer to flow rating. For example, 9625 is a 625 CFM AFB carb. Adding 0, 9625 means it was set up for a Chevy style linkage, adding 1, 9626, means it is a 625 for a Chrysler, adding 2, 9627, means it is for Ford; adding 10, 9635, means provision for EGR. If the carb is an aftermarket version, it will have a 9xxx cast in the front near where the mounting stud goes through.

[radjeeper]

So I gather that this means that all Edelbrock AMC Performer intake manifolds have big ports and thus are good?