I want to keep the engine compartment stock looking but want to beef up the motor.I have a 402 bored .030 over and a set of 290 heads with bigger valves (2.19/1.88).the intake is stock with a 4bbl rochester(worked).will the intake be the down fall of possible good hp numbers? just would like to know if anyone has run into this and if so what can i do to make this combo work.this motor is for the street.solid lifter,flat top pistons(10.50 to 10.75 comp),96cc cambered. thanks for the help,red :D

Well, it certainly won't help any. If you're dead-set on keeping the cast GM unit, then there's not much use in talking. You might think about getting a performer and painting it chevy orange. I've seen that before. That's an option.

Put it together and see what it does.

Then put a Performer RPM or something on it and see what it does.

I suspect you'll be left wanting to get rid of that stock piece, and paint the other one orange.

Given the variation in stock intakes, a painted aftermarket one doesn't have to be very obvious, if chosen reasonably.

I don't think you'll have 10.50 to 10.75 comp in a 396 with flat tops and 96 cc chamber heads..more like 8.8-9.0 to 1 or so
As a comparison,I have a 1967 396 with .180 dome pistons with 101 cc chamber heads,and its about 9.75 to 1

Given the variation in stock intakes, a painted aftermarket one doesn't have to be very obvious, if chosen reasonably. '70 used the super-low-rise FLAT intake... not too many aftermarket manifolds look like that! smile.gif

Those sunken manifolds are not the greatest thing for HP. Just changing one to an earlier non sunken design makes enough difference you can definately feel it in the seat of your pants.

'70 used the super-low-rise FLAT intake Yuckkk!!! The good old upside-down intake, where the carb flange is actually below the valve cover flange. The A?F mixture has to make 2 180s to get into the head port.

That's the infamous "Vette" intake that people pay extra for too.

I took one of those off my 74 454 Caprice convertible and put a 69 one on, it made an ASTOUNDING difference.