'73 400

[rayderluvr]

I have been doing a lot of reading and research on my '73 Charger SE. From what I have found, the 400 four barrel is 260 (net) horsepower stock. Is this engine what I see others in this forum refering to as the 400 HP?
I also found that the 400 two barrel was only rated at 185 horsepower (net). Does the four barrel carb make that much (75 horsepower) difference or were there other things different on the four barrel engins to boost up the horsepower?

Thanks!

[ODZKing]

There were only 2 400's in 72 according to the book.
There were 2 different cams and crankshaft - 2 or 4 bbl.
So it not just the carb that makes the difference.

[Scaregrabber]

Single exhaust on the 2 bbl as well. It did feel like at least 50HP difference when you drove the two.

Sheldon

[71bee]

The HP engines had different sized valves in the heads, bigger cam & yes, those good ol' Thermo-quads will help push some ponies!

[BSB67]

The HP engines had different sized valves in the heads.....

No.

[71bee]

The HP engines had different sized valves in the heads.....

No.

Really? it would only make sense to have larger intake valves for a four barrel vs. a 2, right? when did ma MoPar change that rule?

[ODZKing]

I just looked up part numbers for 73 400 heads, interesting.
The number 3671640 is same for both 400 and 440 - 2 and 4 bbl.
However looking up valves it does have seperate listings for 2 and 4 bbl.
2bbl - 2899036 (quan
4bbl - 3512095 (quan
Not oversized.

[John_Kunkel]

All open-chamber BB heads have the same 2.08" and 1.74" valves regardless of HP, only the pre-'68 closed-chamber heads had different valves depending on HP. The part number 3671640 is casting number 3462346, commonly referred to as the "346 head"....the different part number for 2/4 barrel relates to material, not size.

[rayderluvr]

Thank you all for your responses! So thre is a camshaft difference between 2 bbl and 4 bbl 400 engines but heads are all the same.....

[BSB67]

All open-chamber BB heads have the same 2.08" and 1.74" valves regardless of HP, only the pre-'68 closed-chamber heads had different valves depending on HP. The part number 3671640 is casting number 3462346, commonly referred to as the "346 head"....the different part number for 2/4 barrel relates to material, not size.

John, when did they use something smaller than 2.08" intake on a BB?

[c00nhunterjoe]

To my knowledge the intakes were always 2.08, the exhaust could have been 1.60, 1.74 or 1.88 dependeing on the casting numbers

[Scaregrabber]

73 valve sizes are all the same on psgr big blocks. Different valve springs on the 4 bbl heads though.

Sheldon

[John_Kunkel]

John, when did they use something smaller than 2.08" intake on a BB?

The original 350 and 361 BB had 1.95" intake valves with 1.60" exhaust valves.

[BSB67]

John, when did they use something smaller than 2.08" intake on a BB?

The original 350 and 361 BB had 1.95" intake valves with 1.60" exhaust valves.

Figured that it was the 350, was not too sure on the 361