Thermoquad float selection help

[Brooks James]

This bad boy from a 74 360 engine HD truck, which means that it was exempt from passenger car emission standards same with motor homes and industrial engines

It's getting a through reconditioning, and the modifications , some Ive known for a while, one new one here that blew my mind, going to up to a .130 needle and seat
Another member is running a .120 seat at 9 psi, which markedly increased his power markedly

These are floats from 7 different TQ's
They look pretty uniform to me

What are the pros and cons for brass floats vs nitrophyll
In the past years I've seen plenty of "new" brass floats I wouldn't think about using

 

[66fs]

I use brass floats, original if I can find them.

 

[GTX JOHN]

Nitrophyll for me.
Too many issues with Blass leaking anymore.

 

[Syleng1]

I’ve always used brass but agree- it looks as it no longer as dependable as they used to be. Either made elsewhere or just no quality control.

How has the plastic held up with the corn juice?
Syleng1

 

[RustyRatRod]

You need to be very careful if choosing brass. Most of them are soldered onto the arms upside down. ...and no, I ain't kiddin. So I have started using the Nytrofil.

 

[Brooks James]

You need to be very careful if choosing brass. Most of them are soldered onto the arms upside down. ...and no, I ain't kiddin. So I have started using the Nytrofil.

You best me, I got a kit with 2 new floats and one was gobbed with solder, they weighed close to the same
Zero quality control

 

[Bewy]

Nitrophyl.

Although I have 'heard' of a Nit floats becoming fuel logged, but I have never seen one & have been working on these since the 70s....

 

[townsend]

This is a direct quote taken from a 1970's Carter carburetor technical publication:
Brass Floats vs Nitro-Phyl
In many applications the old reliable brass float has been replaced with the nitro-phyl design. Although it is more expensive, it will withstand the higher operating temperatures. These higher operating temperatures cause expansion and contraction of the upper portion of the brass float which results in cracking.
The old method of checking brass floats does not apply to the nitro-phyl design. The nitro-phyl float is checked by weight --- the 21-252 float used in all Thermoquad carburetors should weigh 7.5 to 8 grams.

 

[Brooks James]

This is a direct quote taken from a 1970's Carter carburetor technical publication:
Brass Floats vs Nitro-Phyl
In many applications the old reliable brass float has been replaced with the nitro-phyl design. Although it is more expensive, it will withstand the higher operating temperatures. These higher operating temperatures cause expansion and contraction of the upper portion of the brass float which results in cracking.
The old method of checking brass floats does not apply to the nitro-phyl design. The nitro-phyl float is checked by weight --- the 21-252 float used in all Thermoquad carburetors should weigh 7.5 to 8 grams.

Love it, directly from the manufacturer.

 

[S'cuder]

These aren't exactly cheap, but OEM Carter.
Carter 21-252 Carburetor Float - Carter Performance 4-BBL ThermoQuad 800 CFM | eBay

I've bought from these folks several times. They're good people. I had a problem once and they took care of it immediately.

If you check the "Save to Watch List" button, in a day or two they will offer you a slightly discounted price.

I don't know if these are the exact floats for your TQ, so be sure to check.

 

[Brooks James]

These aren't exactly cheap, but OEM Carter.
Carter 21-252 Carburetor Float - Carter Performance 4-BBL ThermoQuad 800 CFM | eBay

I've bought from these folks several times. They're good people. I had a problem once and they took care of it immediately.

If you check the "Save to Watch List" button, in a day or two they will offer you a slightly discounted price.

I don't know if these are the exact floats for your TQ, so be sure to check.

Thanks, I pulled the floats I posted from 7 TQ's looks like 3 different manufacturers, all very close with minor differences , so I would guess the ones they have will work