Head Games!
Yes, AJ...as long as it breaks the 12 mark I'll be a happy camper. Street only. Stock suspension, worked over with new bits, but still stock. The only track time it might see would just be for the ET slip. But most likely not even that. Just want the "butt-dyno" to be happy.
Well in that case, as I posted the numbers, you don't need 400hp to have a chitload of fun.
My combo has undergone three iterations, the smallest of which went 12.9@106 right off the street with 3.55s.The Wallace makes 106 mph to be ~335 hp, easy peasy with a 360.
I'm gonna go back to mind my own business now, but I'll just add that if the whatever gears are currently installed, leave them there and take it easy on the cam, you will only need about 222 to 230 degrees intake duration to hit your target. You can probably mill those 12/1 pistons to get the shape you need with open-chamber heads to get you a tight Quench. After that adjust the compression with a dish to work with the cam you chose.
I suggest you put the power into the heads, and crank the pressure to the max, so when the big-cam bug bites, that you don't have to start all over.
But more important than anything, I wanna mention, that with a 4-speed your lowest driveable speed becomes an issue.
If you have a 2.66 low gear 4-speed and 3.55s then at 700 rpm, your lowest speed becomes 5.9 mph with an 84" roll-out or 26.7" tires. And you won't be driving that with a 292 cam, and 25* of idle-timing.
And if you have to toe the clutch,for any amount of time, that 3600# Zoom-clutch will not be your friend.
The 3.91s will get you down to 5.35 mph, not a whole lot better.
If you expect to be driving slowly on a regular basis, you are gonna need to bring the idle-speed down, and retard the thechit outta the timing. AND, your Transfer slot sync is gonna have to be spot on.
To get down to 4mph with 3.91s, your idle speed will need to get down to 523rpm. Your 292 cam will not go there no matter how far you retard the timing; it will not have enough power to pull itself. And on the way down, it will start bucking like a wild horse.
If 4mph, which is a fast walk, is important to you then yur gonna need to get around the gearing issue, or stick a small cam in her, which will have more low-rpm power so you can hit that 523 rpm target.
I'll tell you what I did.
I swapped that 2.66box out in favor of a Commando box, which has a 3.09 in it, and I installed 3.55s out back.
Now 4.0 mph is 552 rpm. And I got rid of the 292 cam, in favor of a 270/276/110. Which would idle down to 552 no problem; but I had to retard the Idle-Timing to ~8* to get it to stop bucking. This cam had lots of power down there to pull itself around on anything including grass.
But you have 3.91s so your target is 608rpm with the Commando box. That means, if you wanted to, you could install the next bigger cam, say a 276/110 cam, but you may need to retard the timing a lil further to get rid of the bucking.
I tell you these things cuz I'm working up to something;
namely, the 270 cam is pretty small, about 223*@.050. To make power with that small a cam, I used OOTB Edelbrocks, and pumped the pressure to 185 psi.
This was an excellent combo. I put enough valve spring on it to regularly rev to 7200. And that lil cam did pretty darn good up there, posting 106mph in the quarter with 3.55s in Third gear, reving 6600.
And the best news is, geared for 85=2100/65=1600, and with a set-aside carb tuned for economy, this thing killed it; posting nearly double of what I was expecting.
This was and will ever be my favorite combo. The next bigger cam I installed; a 276/286/110 cam, took me months to sort out, and cannot touch the previous cam as to fuel-economy nor bottom-end torque, and seems only a lil stronger on the top, despite the track results that say otherwise.
BTW
To retard the timing on the fly, I installed a dash-mounted, dial-back, timing retard box. You might as well get one, cuz it will cut your tuning time drastically. And there is no other way I can think of, to retard your timing from say14* at 750 to 5* at 550, which is what it's gonna take to soften the power pulses to keep you out of the Prancing-Pony rigamarole.
