TT5.9mag
Two atmospheres are better than one
I agree with @Garrett Ellison they’re both terrible. The good news is you won’t notice which one is more terrible-er.
I thought of that, but I'd just use one of my dual plane 4bbl intakes before purchasing another. Doubt this truck sees enough mileage per year to fret over a mile or 2 per gallonif you're trying for a mileage miser build, have you considered hunting down an SP2P?
left hand hurts as much as the right hand.....I agree with @Garrett Ellison they’re both terrible. The good news is you won’t notice which one is more terrible-er.

facts. unless the mileage gain is appreciable, it's all a moot point besides driveability.I thought of that, but I'd just use one of my dual plane 4bbl intakes before purchasing another. Doubt this truck sees enough mileage per year to fret over a mile or 2 per gallon
100% it's about part throttle under 3000 rpm's drivability between the two intakesfacts. unless the mileage gain is appreciable, it's all a moot point besides driveability.
i'd almost suggest that the factory dual plane is better than the SP2P if set up right. we certainly know it's a better all around piece.
it's an interesting exercise to be sure.100% it's about part throttle under 3000 rpm's drivability between the two intakes
Or any dyno.it's an interesting exercise to be sure.
my gut check says the dual plane version out classes it, especially in that 2000~3000 range. but early single with small ports and small valves and small carb? i'd bet it'd be hard to quantify the difference with the butt dyno.
Driving the older style intake/cars, even in B-bodies, were tire friers. My sister had a '70 Coronet 4 door, and that 318 2bbl had punch that many would doubt it was even a 318 2bbl. Just curious on the comparison between the two, because I'd use either or.....it's an interesting exercise to be sure.
my gut check says the dual plane version out classes it, especially in that 2000~3000 range. but early single with small ports and small valves and small carb? i'd bet it'd be hard to quantify the difference with the butt dyno.
what you need is a dyno for ants!Or any dyno.
oh for sure. every early 2bbl car i had would one wheel peel whatever shitty 14" tire i had on there half way down the block easy money.Driving the older style intake/cars, even in B-bodies, were tire friers. My sister had a '70 Coronet 4 door, and that 318 2bbl had punch that many would doubt it was even a 318 2bbl. Just curious on the comparison between the two, because I'd use either or.....
I doubt it. In fact I’d bet (within the useful range of the dyno) you could make two pulls and not even notice there were two graphs. Using the same engine and two different stock cast iron 2 barrel intakes. They’ll make the same power so they’ll use the same amount of fuel.what you need is a dyno for ants!
(but in all seriousness, maybe you could glean some information from fuel consumption data)
define "useful"I doubt it. In fact I’d bet (within the useful range of the dyno) you could make two pulls and not even notice there were two graphs. Using the same engine and two different stock cast iron 2 barrel intakes. They’ll make the same power so they’ll use the same amount of fuel.
Useful;define "useful"
;D
so noted.Useful;
able to be used for a practical purpose or in several ways.
Practical
Functional
Not from DTM
Merriam-Webster added that last part after AI gathered information from FABO.so noted.
what you need is a dyno for ants!
(but in all seriousness, maybe you could glean some information from fuel consumption data)
ET slips may show something measurable. Especially if done back to back, then back againI doubt it. In fact I’d bet (within the useful range of the dyno) you could make two pulls and not even notice there were two graphs. Using the same engine and two different stock cast iron 2 barrel intakes. They’ll make the same power so they’ll use the same amount of fuel.
Not if you never go WOT!ET slips may show something measurable. Especially if done back to back, then back again

If that is the single plane you've got, go with the dual plane.Thinking on doing a 318 over the winter for the truck. Will be a LA roller block, and I don't care about WOT.
I have not tested anything with the early year (like the '69) single plane vs the later year intake. Thinking best torque/power up to about 3000 rpms.
At this point, I know pretty much the rest of the build, just wondering if anyone has compared these intakes. At this time, this direction, it will be the BBD 2bbl. As always, I may change my mind... LOL
As in older intake, the picture below references what I'm talking about
View attachment 1716453393
Good thought!If that is the single plane you've got, go with the dual plane.
Why, you ask?
Because of that stupid bathtub choke well that constantly eats gaskets leaving you with another frustrating exhaust leak right next to the carburetor.
You won't notice a lick's bit of difference performance-wise, but by the time you replace your third gasket you'll be wishing you had used the dual plane with a sealed choke well.
View attachment 1716453681
Not if you never go WOT!
![]()

Adding this to a 318 does not work, 360 ports are to big. i know from experience, engine will not run right until full operating temp, i removed this and went to the original 318 intake then all goodDon't know if you've got one sittin' around, but for the sake of argument a stock 360 2bbl manifold and carb is an excellent bolt-on addition to a stockish 318. All your planned linkages will work. If you don't have one already, they can be had for a song.
View attachment 1716453658