My plans are to use an EFI lower intake manifold and fab up a collection chamber that combines 3 ports into one and tig weld it to the the manifold. Then im going to make a plate that bolts to the top of said collecting chamber and has been cut to fit a 2 barrel carb. Im going to make to of these to make a 2x2 intake manifold. What material would yall recomend making the fabricated peices out of to mount the carbs on? I was thinking some type of aluminum and Im sure the guy at my local welding shop could recomend something but I wanted hear your opinions first. I plan to use autolite 2100 carbs. Are these good reliable carbs that are easy to adjust?

Thanks, John

 

Here is a rough sketch of the plan. Please excuse the dirty lense lol

 

Make the plenum from 1/8 aluminum plate. Make the top from 1/4 or 3/16 plate. Don't forget to angle the top pads about 4 degrees so the carbs are level.

2100 or 2150 carbs are the best. I prefer them over Holleys as they are easily serviceable and have fewer sources for leaks. I use them a lot. They are available in bore diameters from .98" to 1.33 ". Here is a pair of 1.02s we put on a 300-6 drag car:



And another set of 1.08s on my hot rod coupe:

 

Thats awsome! Ill probably do like you did and get some spacers that are already angled and weld those on to mount the carbs to. I just hope that out of the 3 2100 carbs I found for an awsome deal on ebay 2 of them have the same size bore. Just wondering, what would be the best bore size to run on the 300? I love your blue drag car the engine is a monster! Maybe one day when I get out of high school Ill have one like yours.

Thanks, John

 

Look on the side of the main casting behind the throttle linkage. There will be a bulls eye with a number stamped in the middle. That is the carb size. The most common sizes around are the 1.08s used on lots of 302 V8s and 1.21s used on 351, and 400 V8s. Two 1.08s work well on the 300 - I plan to upgrade the 1.02s on The Frenchtown Family Truckster when I get a chance. But a single 1.02, 1.08, or 1.21 would certainly be an improvement over the stock 1V. If there is a cam on the underside of the throttle shaft that actuates moveable metering rods it is a 2150 series. It is a 2100 series if it does not have this feature. With the 1.08s in the yellow ****** I can drive it in off the street onto a drag strip and run 13 second quarter mile times with it on street tires. The Truckster runs 11s with 2.47 rear gears and the 1.02s.

By the way, none of my engines use a heated manifold. Way overrated if you ask me.

Thanks for the compliments. The 300 six in my blue altered is putting around 488 HP to the ground so it probably puts out around 550 at the crank. I never dynoed it. It uses three 540 cfm Holleys.

I started building my first roadster when I graduated from high school. It took me five years. I recently saw that car at Bowling Green Kentucky after selling it forty years ago. Thank God nobody died in that car. I must have done some things right.

Good luck with your first build.

 

Thanks French that means alot to me. If it isnt top secret and you dont mind sharing could you tell me the specs of the truckster engine please. I understand if you dont want to though.

Thanks, John

 

The Truckster is nothing special. It is mostly used and used up obsolete parts from my racing operation.

P & P head
1.90 / 1.6 valves
roller rocker arms
flat top hypereutectic pistons
stock bottom end - cast crank and stock rods
Schneider roller cam - bracket and short track grind w/ .600 lift
2 x 2 intake w/ two Autolite 1.02 carbs equivalent to 370 cfm 4V
home made headers
Mallory dual point ignition

1.82 'Glide
4000 stall converter
2.47 rear gear ratio


Thanks for asking.

 

Awsome thanks for sharing. One more question and I promise Ill let you go lol. If I were to use the efi exhaust manifolds instead of the long tube headers will i notice any loss in power. Im tired of have to squeeze, bend and, break my hands and fingers to bolt and unbolt them. The thought of changing a starter with them on scares me completely! Plus with the efi manifolds i can bolt them and the intake on the head while its sitting on the bench and then use a lift to set it onto the block. What are your opinions?

Thanks, John

 

I recommend the cast EFI manifolds for a street driven vehicle. When you put a full exhaust system behind the manifolds there is very little difference in performance. Agreed, tubular headers are a pain.

 

Well today the ups man dropped off the intake. I have to say it looks almost brand new minus the strange red paint sprits here and there. Got it off of ebay for 75 bucks and free shipping. Pretty good deal if you ask me.

 

Anyone know what's up with the red splotches?

 

The more I look at it the more I think its just something from the pick and pull yard marking its sold or needs to be pulled. Who knows. I hope everybody had a happy and safe Christmas. Im ready to get this project underway but I havnt got the metal yet and everybody is closed which is expected. Which grade aluminum and how much do yall think I will need?

Merry Christmas, John

 

Somebody had to swoop in and out bid me 4 seconds before the bidding ended on the 3 2100 carbs! One minute I was winning and the next second the bidding ended and I thought I had one when it popped up and said I had "just missed out" I was p****d! So now i had to start over and started to search when i remembered....... I have 2 holley 4160 vac secondary 4 barrels in the garage. So questions, are two 600 cfm carburetors to much for a built 300? Is there a way to tone them down to about 400 cfm a peice?

Thanks, John

 

Don't bother with (2) 600s. You would not like the results.

Autolite 2V carbs can be had dirt cheap - nobody wants them. And few have discovered their potential. I'm betting a want ad in your local paper will get you a wheelbarrow full for about the price of a Holley rebuild kit. Around here I find them all the time for $5.