AJ/FormS said

Yeah well the '74 is a 8/1 advertised, and with the stock cam in at 108, the Wallace predicts 136psi at 800 ft, with a miserable VP of 113. But we all know that a 74 is not actually an 8/1 engine at all, plus OP's has some miles on it, so it won't be in at 108 anymore, if it ever was..
AND
OP is in Colorado!
Lets say the Ica of the stock cam is 50* and Elevation is 4000, and the Scr is 7.8; The Wallace now predicts
a paltry 113 psi/ with
a VP of an abysmal 93.
That's your baseline with the stock cam.
----------------------------------------------
Now, lets see how the Whiplash fairs
The only thing I'm gonna change is the ICA from 50*, to 55*; and I get
108psi at
86 VP
@4000ft elevation.

But suppose OP is at 1000 ft
The Wallace then predicts:
123 psi@ VP of 98

I don't care if your name is Smoky Yunich, this is a dead dog engine until it gets up on the cam, which is a 213/226/109 @.050, so it ain't happening for a long time, even with 3.55s, cuz the factory stall mightabin 2000, and now with the paltry cylinder pressure, is gonna be even less.

And OP has verified this sad situation in post #45.

There; done!

Op; you can't fix this with gears.
You can get around it with a higher stall. But that cuts into your working rpm, which then requires a cam that extends the rpm higher, which then requires another gearchange, and on and on and on.
If you are at elevation, the situation quickly makes the car
NOT a DD anymore.

In a given engine, the best way to solve this is with a higher starting cylinder pressure. and Second best is slam that intake shut sooner. You need a fast rate of lift, Solid-Lifter cam, in a smaller than normal size, which I haven't seen in a long time.
Something with an Ica close to stock of 48* and then you'll get at least your stock pressure back.

But, just to be clear
In your current set-up, the high-stall is your best bang for the buck.
When I run a 318 auto, I like my 2800; that's what I always run.
but I am at 900 ft, with a stock cam, and I run whatever gear I want, and my 318 measured 140 psi to start with. It goes like snot with 4.30s!/ not bad with 3.91s/ slowing down with 3.55s/ and with 2.76s, I manually upshift ASAP and let the Thermoquad wail to like 80mph still at 2800..................... big grins all around.

BTW,
Without regard to stall speed;
a good VP number to shoot for is like 150, but you'll never get your teener there with any reasonable cam, unless you spend a boatload of cash on machining.
But 140 is doable, and runs fairly decent.
By 130VP, she's getting lazy, and a convertor is my go-to.
By 120VP, I ain't bolting nuttin on that stone.
By 110VP, I'd be embarrassed to be seen driving it
By 98VP, she's feeling like a tired 273.
By 86VP, it's about as snappy as stock slanty, and she's a lawn-ornament.
Them there are my opinions.

Here's the thing; that Whiplash, at 213 @.050, is gonna make peak power at around 4600/4800, and peak torque maybe as early as 3100/3300
Your 1-2 shift rpm, if you outshift at 5000, will drop in at 2950, but your roadspeed might only be 40mph(with the 3.55s). So on the shift into Second/1.45 ratio, you'll be doing ~40mph @2950rpm, and with no reasonable VP forthcoming ........................... you'll be able to measure your acceleration with a sundial........ The cam will start working again at say 3600, which will be 50mph. So that makes the hole to be from 40mph to 50mph, am I right?
I'd be looking at a stall speed of between 3200 and 3600 depending on how punchy you want the 1-2 shift to be. Then I would retard that cam several degrees to pump up the useable rpm, cuz I would no longer be worried about how low the VP is going. And then I would gear the car to run out of revs at 65mph in second gear. And then I would go out and have a blast. This assumes you are at or below 1000 ft elevation.
But if at 4000 ft, or higher, I would hire Myth-Busters to see how far they can trebuchet that slug, and go build me an alloy-headed 367 that pumps out closer to 200 psi. Or better yet, a cool as a cucumber, 383/400lo-deck-stroker.
Lemmee know if you need;
>a K-member,
>a 383 core,
>a SG 8.75 with 4.88s,(that's all I still have,bigger than 3.55),
>a fat driveshaft,
>some bigger T-bars,
> factory disc-brakes
And so on, lol.
sorry no trans .......................
unless you would like a 4-speed, lol.

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