'77 mopar 400 cam swap

casey henson

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would like the try that comp 268H on a 108 though.
 

rumblefish360

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HP exhaust manifolds with 2.5" pipes dumped at the axle,performer RPM intake, 850 AVS2 carb, on an otherwise stock 77,400 with 25K miles on it.
The converter and gear are staying the same.
And that is my question, what is the converter’s stall and what gears? Tire size?
would like the try that comp 268H on a 108 though.
Call Comp and ask for that mod. I did it for my 340 cam. Moved the 110 to a 108.
image.jpg
 

gtxrt

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my first after market cam back in about 1977 still have the card lol. there was a crane fireball series not sure if this is it. 222-222 on a 112lsa

20220721_130901 (1).jpg
 
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rumblefish360

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I ran a Crane HMV 278 in a 9:1 compression 400 I built. It was 222/234 duration and 467/494 lift with a 114 lobe separation. It is almost identical specs to the larger summit cam 6401. it was a nice street cam but probably one step too large for your car with lower compression and higher rear gears.
I remember now (thanks for the memory jog) it had “HMV” on the cam card.
 

rumblefish360

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my first after market cam back in about 1977 still have the card lol. there was a crane fireball series not sure if this is it. 222-222 on a 112lsa

View attachment 1316284
I noticed the address was s not where they ended I’m is in Rlorida because it was listed as Daytona, Fl. Your says “Hallandale Fl.” There is also a lack of duration numbers anywhere on the card. I do like the specs to check the cam at both .050 & the advertised .0035.
 

casey henson

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Just a quick question...

Does anyone know the specs for the stock cam in a '77 model 400 ?

I have dug quite a bit and have not come up with this answer.
 

Geoff 2

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Post #29 is bad advice. Tight LSA only gives a rough idle if the duration is too big.
Production Mini engines had 107.5 LSA cams with 230* adv duration. Small engine, small duration. Idled smoothly with 107 LSA.
DV has 3+ pages of cams listed in his SBC book. From mild to wild...
The mild cams [ good idle, good vacuum ] have the same LSA as the wild...
What changes is the duration. The LSA changes [ decreases ]for the cu in.
Mild 302 has 110 LSA; mild 434 stroker has 102 LSA; both have 199 @ 050 duration.
If you want tight, how about Jon Kaase's EMC winning 400 SBF. 95 LSA cam, 92 ICL. It made 663 hp @ 6000 rpm & was making 478 ft/lbs @ 2500 rpm. Did all that with a SFT cam, just 246 @ 050. Cam also had less exh duration, 238 @ 050. And short R/S ratio. Many lessons in that combo.
 

gtxrt

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stock cam for fact has 113 LSA according to the chart in the book. guessing 206-209 duration @ .50 with 425-431 lift
 

casey henson

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I am a little surprised the factory cam lifts are that much. I was expecting something under .400
 

Photon440

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I recall that the factory didn't do much to change the cam profile even at the end of the big block production, but they retarded the cam 4 degrees to reduce cylinder pressure at low rpm.
 

qkcuda

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The 400 cam looks like the pre-magnum 383 four barrel cam. The old 383 (and 361) two barrel cam was only .390 lift.
 

gtxrt

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The 400 cam looks like the pre-magnum 383 four barrel cam. The old 383 (and 361) two barrel cam was only .390
The 400 cam looks like the pre-magnum 383 four barrel cam. The old 383 (and 361) two barrel cam was only .390 lift.
you could be right. the .390 was used in 1966. digging deeper, then in 1967 the 383 non performance went to .425-.437 not .425-.431 like i posted before . my book only goes to 1972 and it said 400 in the chrysler was .434-.434
 

gtxrt

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not sure it matters but melling replacement cam has 208-210 duration @.050 and .431-.429 lift
 

RemCharger

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I don't see anything too wacky compared to this one? :popcorn:
20220722_125904.jpg
 

PRHeads

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That one has a similar anomaly, but to a lesser degree.

Maybe “problem” wasn’t the correct choice of words.

How about an “oddity”.
 
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