Hello, looking for advice on an intake manifold.My combo is a 402 .030 over slight domed pistons. Closed chamber oval port heads with large valves. 102CC combustion chamber makes aprox. 9;5 to 1 compression.Using a Comp cam 270H Magnun Hydr.Stock 1972 402BB intake and Carb with up jetted secondaries. It made 403HP at 5200 rpm. Looking for a little more. Alos stock appearance is important as I show my 1972 Chevelle SS 402BB. Auto TH400 10" conv 2600RPM stall. 3;42 gears. any help would be great!
Gary.

are you using the LS-5 stock intake? the one that is a really low intake? if so you might see a small gain using the higher rise stock intake that was made for the bbc. i believe they was used on the higher output motors over 390 hp.....most bbc with 390 hp rating or smaller got the low rise intake......i had a few of the stock high rise bbc intakes but never really tested them over the low rise to see if there was any difference.......i guess you could always buy the performer intake and grind off the markings and needle scale the intake to look stock and paint it.......there was some factory alum. high rise intakes for the bbc but i think they was all for square port heads not sure if any was made for the oval port.....someone else might have alittle more info in this dept.....

You can use a cast iron high rise that came on a 396's/427's up to 1969 if you want to remain looking stock..or get a Performer RPM and paint it orange.

Thanks for your replys,any other thoughts would be appreciated. Do you think with my combo the performer or the performer RPM would best suit me?

There were a couple different factory aluminum oval port intakes,but there is only a tri-power and a quadrajet version.They were only on 400 and 390 horse 427s. Makes things kind of limited with a stock apperance in mind.

Thanks L89, have givin my eng specs. what intake would anyone recommend.After market or O.E.
Thanks for your replys!
Gary.

Just catching up on some reading and saw this post. I agree with using an RPM or RPM Airgap for ovals. A recent comparison in July Hot Rod placed those intakes at the top.

Jeff

RPM for sure IMHO...

Originally posted by SSJeff:
A recent comparison in July Hot Rod placed those intakes at the top.

Jeff What intakes did they test?

What was the date of this article/magazine?

..I think it was the June or July "Hot Rod"
..they tested a ZZ454 (454HO shortblock w/aluminum GM oval port heads) the intakes where:
Stock GM aluminum (looks like the RPM)
Performer
Torker
Victor Jr.
RPM RPM Airgap

The motor lost tq/hp using the Performer and the Torker (and RPM was worth 29 more HP/20 ft. lbs. of TQ vs. the Performer,and produced more peak torque at 4000 rpms)..the numbers for the Victor Jr. wheren't good either..the RPM and the Airgap had the best numbers,and the GM intake was close to the pair of RPM's,at least on this motor.

The Torker :rolleyes: like there's a fair test graemlins/clonk.gif tongue.gif

Great info keep comments coming please! My intake is very low almost flat. I should see some improvment with the Performer 2-0???? rather than the RPM manifold. My Comp Cam is good to only 5500 RPM. Any advice is appreciated!
Gary