Aftermarket Intake vs Stock intake

[68stcracing]

Stock 2 bbl intake or Edelbrock # 2101, 2701 or 2716 with 1" adapter/ using a gauge legal 4412 Holley. The motor is 355 9.5:1 Stock open chamber head, ported with 2.02/1.60 valves. Chevy small block, 3100 lbs dirt track factory stock racing on kk704 American racers
1/4 mile tight dirt oval. Rev limit rule of 6700 rpms

[68stcracing]

Also allow Weiand 7547, 7547-1

[barnym17]

aftermarket for two reasons 1 weight, 2 the stocker is designed for very low rpm operation not much more than 4800.

[mag2555]

If on the track your motor never, I mean never! drops below 4000 rpm I would go for the single plane model, if not than the air gap model.
On any of these be sure to epoxy in all the dam fitting holes on the roof of the ports if you can.
In some areas where you can't get your finger in the runner to smooth the epoxy out its best to just pack epoxy in the cup side of a pipe plug itself to level it off and then use Telfon tape to set its depth in the manifold level with the roof of the runner, and depending on what the Manifold rules may be this may be the only way to get them closed off and level.
Any Vacuum lines you may need should be teed off the Carb.
Also in regards to your heads the open chamber heads dispite flowing more intake air in stock form then earlier heads make less power giving the same compression ratio, in reworked form they will need to flow 5% more air to make up this difference.

[Ron E]

A friend of mine trying to ID the weakest links stuck a lowly EB performer on his stocker. It was .2 quicker than his legal intake.

[pdq67]

A friend of mine trying to ID the weakest links stuck a lowly EB performer on his stocker. It was .2 quicker than his legal intake.

You mean the, "original/1st", E-Brock 2101 that has a flat on the top rear runner for dizzie clearance?

pdq67

[Brian W]

I would definitely use the 2701. I have tested it over the 7547, and stock manifolds extensivly. 2701 is the top performer. The single plane is close in upper RPM power but does not come close to the 2701 at low RPM. 2701 makes far more avg power.

[Ron E]

A friend of mine trying to ID the weakest links stuck a lowly EB performer on his stocker. It was .2 quicker than his legal intake.

You mean the, "original/1st", E-Brock 2101 that has a flat on the top rear runner for dizzie clearance?

pdq67

Not sure which number, but this was 10, or more years ago. So, its sure to be a early version. Is the early one better, or worse?

[68stcracing]

Choosing between a mercruiser 5.7 vortec 2 bbl intake/4412 gauge legal with adapter, or the edelbrock 2716 with any adapter plus gauge legal 4412, Which do you think is better for a 1/4-3/8 track?