From the factory, did the TNT have the same carb as a standard 440?

It will depend on the year as noted above. It will also depend on the application.

Dave
 
There were several carburetors (mostly Carters WCFBs AFBs and AVSs from the mid- '50s thru' the mid-70s and the TNT years were mostly the late '60s thru' the mid-70s with just a very small spattering of Holley's thrown in during the same time frame depending your size engine your car was built with and If California Emissions were involved, And 727s 3spd+4spds and even convertibles could change which carborator was used. Somewhere I have a complete list of all the carter's used broken down by engine size and years. Tell me what year and engine size you're playing with and I'll dig out that list and tell you which # your car left the factory with, Jer
 
Last edited:
It's not so much about any year in particular. Here's why I was asking --

The 68 300 we recently acquired had the 440 "converted" into a TNT by the PO. I put that in quotes because I don't have hard facts about what was done, but according to him, he had the engine out and had a cam installed that had specs similar to the OEM TNT cam. The engine also has the HP exhaust manifolds, dual exhaust w/ crossover, dual point distributor, and a Holley 670 cfm carb (it's a Street Avenger I'm pretty sure). The car, btw, has a 3.23 rear and 4 speed.

I'm basically wondering how much benefit, if any, would be acheived by going with an aftermarket dual-plane manifold and a 750cfm carb. I read that the Six Pack's 3 carbs gave a total flow of 1200cfm so it leads me to believe that this engine might turn out some extra ponies if I increase the flow. But it's running really pretty well right now so I don't want to upset the apple cart for just a few HP if that's all it would net.
 
If you look in the Factory Parts Book there is a table in the fuel section.
For 69 it appears they are different.


Alan
 
Yes a 440 HP had a different carb compared to a standard 440 in the years 1967 through 1971. Same intake manifold.

I don’t know about other year 440’s
 
It's not so much about any year in particular. Here's why I was asking --

The 68 300 we recently acquired had the 440 "converted" into a TNT by the PO. I put that in quotes because I don't have hard facts about what was done, but according to him, he had the engine out and had a cam installed that had specs similar to the OEM TNT cam. The engine also has the HP exhaust manifolds, dual exhaust w/ crossover, dual point distributor, and a Holley 670 cfm carb (it's a Street Avenger I'm pretty sure). The car, btw, has a 3.23 rear and 4 speed.

I'm basically wondering how much benefit, if any, would be acheived by going with an aftermarket dual-plane manifold and a 750cfm carb. I read that the Six Pack's 3 carbs gave a total flow of 1200cfm so it leads me to believe that this engine might turn out some extra ponies if I increase the flow. But it's running really pretty well right now so I don't want to upset the apple cart for just a few HP if that's all it would net.
O.K. I guess I can't help you then. I'll only add that you're playing with a 4500 lb car. It's ah Cruiser not a Street Brawler, and the more you tweak on it the more fuel you'll burn. I know of one Yellow '72 Dodge Monaco Long Roof out on the left coast "somewhere" that's running two 24 Gallon fuel cells, one each rear quarter because he can't make it on one tank full to get him from Phoenix to LA, lol. Have fun with your ride no matter which way you jump,You own the title too I assume? Jer
 
Last edited:
It's not so much about any year in particular. Here's why I was asking --

The 68 300 we recently acquired had the 440 "converted" into a TNT by the PO. I put that in quotes because I don't have hard facts about what was done, but according to him, he had the engine out and had a cam installed that had specs similar to the OEM TNT cam. The engine also has the HP exhaust manifolds, dual exhaust w/ crossover, dual point distributor, and a Holley 670 cfm carb (it's a Street Avenger I'm pretty sure). The car, btw, has a 3.23 rear and 4 speed.

I'm basically wondering how much benefit, if any, would be acheived by going with an aftermarket dual-plane manifold and a 750cfm carb. I read that the Six Pack's 3 carbs gave a total flow of 1200cfm so it leads me to believe that this engine might turn out some extra ponies if I increase the flow. But it's running really pretty well right now so I don't want to upset the apple cart for just a few HP if that's all it would net.
'68 had a Holley carb for the 350HP version and a Carter AVS for the 375HP version.
 
The 4160/4360 Holley used on the Mopar big blocks from the factory was an unreliable POS. This carb suffered from many problems, the unit was famous for secondaries that did not open properly due to poor placement of the velocity port that opened the secondaries. These Holleys were also famous for boiling over after the engine was turned off. The other issue was that the secondary metering port was fixed which made re-jetting of the secondaries difficult. The Holley besides being unreliable, was also on the small side at 600cfm for the 440 engine (that would be with functioning secondaries). The AVS was highly reliable and had a higher flow rating at 800CFM and would be the preferred choice for an engine that was brought up to the TNT standard. On a stock 350 horse engine, there would not be a lot of advantage to the larger AVS carb because the mild cam and log manifolds for the 350hp application would not be able to take full advantage of the higher top end flow parameters of the AVS. There would still be an advantage to the AVS because of it's outstanding reliability. If emissions are a concern, the Holley will run cleaner, but that is not usually an issue on pre-catalyst vehicles at this point in time as most of those vehicles are outside of inspections standards.

The 6BBL carb setup was not offered on Chryslers, but even though it was rated 1250 cfm, dyno results with the stock configuration on the 6BBL engine showed a max of about 925-950 cfm. The stock heads, cam and exhaust limited the flow to those numbers. Significant modifications to the engine were necessary to get to the 1250cfm potential flow numbers for the 6BBL setup.

Dave
 
The 6BBL carb setup was not offered on Chryslers, but even though it was rated 1250 cfm, dyno results with the stock configuration on the 6BBL engine showed a max of about 925-950 cfm. The stock heads, cam and exhaust limited the flow to those numbers. Significant modifications to the engine were necessary to get to the 1250cfm potential flow numbers for the 6BBL setup.

Gotta compare apples to apples.

A 1 or 2 bbl carb flow rate is done at 1.5 in/hg and a 4 bbl carb is done at 3 in/hg.

If you want to compare a 2 bbl carb to a 4 bbl, divide the 2 bbl rating by 1.414. The 6 bbl rating (which was 1350, not 1250 cfm) ends up approx 955 cfm

The 6 bbl had a 350 cfm center and 500 cfm outboard.
 
From the 1968 Chrysler/ Imperial FSM page 14-45 & 14-46

Holley Model 4160 engine 440 Cu In.
Carter AVS Series engine 440 HP

A little tricky to find, but it's there...
 
Thanks for all the info, and point taken BigBarneyCars. I'm not looking to go crazy, but also want to make sure there's not some easy HP being left on the table. If the stock 440HP had a 800 cfm carb then it sounds like there probably is.

I had replaced the 4160 in the other 300 (440 non-HP) with a Holley Street Demon 750 cfm. It sounds like both 440's will be happier if I swap the carbs.
 
Thanks for all the info, and point taken BigBarneyCars. I'm not looking to go crazy, but also want to make sure there's not some easy HP being left on the table. If the stock 440HP had a 800 cfm carb then it sounds like there probably is.

I had replaced the 4160 in the other 300 (440 non-HP) with a Holley Street Demon 750 cfm. It sounds like both 440's will be happier if I swap the carbs.

The street demon is a much improved carb from the 4160. The standard 440 should be more than happy with that unit.

Dave
 
The mopar parts book shows LP and HP classification on their carbs. you could have either depending on wether it was a 335HP or 330Hp, or a California smog, or Factory A/C in a roadrunner/superbee. Clearly Mopar used a wide variety of carb numbers for different applications.
 
From the 1968 Chrysler/ Imperial FSM page 14-45 & 14-46

Holley Model 4160 engine 440 Cu In.
Carter AVS Series engine 440 HP

A little tricky to find, but it's there...

Ah ha, I see that now. When I looked at that page before I didn't notice the HP designation, or more likely didn't pay attention to it since it is the only 440 listed on that page. I guess that's because the standard 440 used the Holley and not a Carter. Thanks for pointing that out
 
Back
Top