Originally Posted by SomeCarGuy
Originally Posted by lewtot184
Originally Posted by furious70
I've done back to back comparisons, same car, same engine, same tires with OEM and SD intake. SD intake and 3.91's, barely spin tires on idle stomp. OEM intake and 3.23's, much more spin from idle stomp. That's proof positive of low end difference.

This was a basically stock magnum 383 spec motor with 268H cam and 906's with normal 3 angle VJ, headers, 750 holley, nothing fancy at all.
i had the exact same experience working on two 383's. the one 383 car with the 3.91's and single plane was a total turd. the stock 3.23 geared 383 would have clobbered the other in a 1/4 mile.


We’ve reached absurdly here. Intake swap cost like 100 ft pounds off idle. Yeah or whatever. Dyno results right in this thread show a variation of about 3% one way or another in favor of one manifold or another at various rpms. But with a simple intake swap you guys killed off triple digits of power. That takes some skill.


I mean, I think I can read, but maybe not. That article shows a 37lb-ft difference at 3000rpm between the SD and the performer. 38 to the Action Plus. If they had tested down lower then that gap would surely increase. It wouldn't take 100lb-ft to make the difference I observed and shared in this thread.
I appreciate your compliments as to my skill in things mechanical as well as reading ability.

70 Sport Fury
68 Charger
69 Coronet
72 RR