Which manifold should I go with?

[coupe32]

I am having another 340 short block built by a machine shop. Currently I am running an Edelbrock performer RPM manifold that I had chromed. I have a RPM air gap manifold that is not chromed. I was wondering if it would be worth it to run the RPM air gap manifold or just stick with the performer RPM manifold since has been chromed. Would I see much differrence in performance? I'm going to run performer RPM heads and SRP forged pistons. Compression will be around 10 to1. I think I have decided on a SSH-25 Racer Brown cam with 238 duration/485 lift. 108 centerline. This will be in a 3300 lb car with a 5 speed manual transmision and 3:89 gears.

[pishta]

Chromed intake will run hot. Airgap, not so hot. A-G also has revised runners making it superior to the RPM. My opinion FWIW is sell the pretty manifold and recoup some of that 340 build money. But hey, its only an opinion. I got an A-G too but moved over to a Pro-Flow EFI setup.

[peg leg]

All the way. Cooler intake and carb, better torque. Would not trade mine for any other.

[fat 360]

Yea keep the Airgap,loose the chromey.

[cudabob496]

http://www.hotrod.com/techarticles/h...lds/index.html

[coupe32]

I will use the air gap. Thanks everyone for the help.

[Zach H]

edelbrock sand casts their intakes. For the best rpm range I would look for a good liquid cast intake like weiand or summit. Ask the company how they cast their intakes before ordering.

[cudabob496]

Originally Posted by Zach H

edelbrock sand casts their intakes. For the best rpm range I would look for a good liquid cast intake like weiand or summit. Ask the company how they cast their intakes before ordering.

whats the disadvantage of cast intakes?

[pishta]

Sand castings can have core shift. Look at the intake ports compared to a gasket, you'll see the misshapen, shrunken, deformed or even shifted ports that may even overlap the gasket! Permanent mold castings (eg. used by Professional Products Cross-wind manifold) produce dead nuts port size, location and a finish that is close to polished right out of the molds. One builder specifies PP intakes over Edelbrock RPM AG because he has seen too many Edelbrock intakes that have overlapping port deviders that cant be sealed by standard gaskets!