For a this application, you want to be in the powerband from say 20 to 40 mph, am I right?
If your power peak is at 5300rpm, and it rolls off the cam at 5600, then 5600 can be 40 mph.
To get there with 27" tires, will require a Roadgear of 10.12@10% TC slip. With a regular torqueflite the ratios are 2.45-1.45-1.00
So then 10.12/2.45=4.13rear gears, rounds down to 4.10s and you use First gear.. 20mph will be ~half that, or ~2800, depending on TC slip.
To the OP;
Now: I'm gonna tell you a secret; the biggest street tire
that you can fit under a 69Dart with factory tubs is a 255........ and with 4.10s, any good 360 will spin those 255s all the way to the top of first gear.
So my 2 cents is this; for a first timer, I would stick to a modest cam in the 218 to 223*@.050 range, on a 106/107LSA, and adjust the Scr to a number that brings the cylinder pressure low enough to not get into detonation on best gas.
Course if you did that, you would no longer need the 4.10s........ cuz these cams will power peak 400 and 600 rpm lower than your contemplated 280 cam; and the cylinder pressure should be higher......
Either of these cams will make your high-pressure 360, plenty powerful enough, to be a 255 fryer all the same, even without the 4.10 gears.
>If it was me, and I needed a convertor, I would get at least, a 2800. But if it was me, I'd get a solid flat-tappet cam of about ONE size bigger than [email protected]
>I didn't talk about lift because for this application, it hardly matters.
>Headers are a must if you want to take advantage of the overlap cycle, that a 106LSA cam will generate..
>If you want the idle of a big cam, without the big cam penalty, get a small Whiplash/Mutha, depending on which one has the lift that your heads can handle.
<Once you start going to/over 6000rpm regularly, you gotta do some oiling mods, so your rod-bearings will live. You might as well do them now, cuz keeping the tach under 6000 when the tires are screaming can be a bit of a chore. Therefore
>If no oiling mods are done I suggest to install a rev-limiter.
> if it was my car, and I had to buy a carb, I'd put a 750DP on there cuz I put that on everything with a 2800TC. If you already have a 4bbl not a 750DP, then just stick anything on there that you already own, cuz again; for this application it won't matter much.
> Here's another secret;
Guys build 400hp 360s that can trap the quarter at 110 mph or better.......... and they need that power to push these old bricks thru the air. Wind resistance begins being a thing, beginning at 1mph, but doesn't add up to much until the speed creeps up past 30/40 mph. Just stick your arm out the window and see.
Your street-rocket never/rarely sees over 65 mph, am I right? .
The power to overcome wind resistance varies by double-double with each doubling of speed. So Doubling the speed, going from 14 to 28 Requires FOUR times the power. From 28 to 56, requires another FOUR times the power. From 56 to 112 is again Four times the power. So you can see that the power is rapidly swapping from going faster, to pushing air.
To get a sense of this; if your body-style requires a typical 30 hp to cruise at 56 mph, it will take 120hp to cruise at 112mph. From 400 hp, this only leaves 280 to continue accelerating with.
In other words;
my 2 cents is this:
why build a 112 mph motor that never/rarely exceeds 65?