360 pros & cons vs 318

You can get scary with any SBM. It just takes a lil more gear with the smaller ones and the scary doesn't last quite as long.
With a 318 you gotchur first gear scary.
With a 340 you get second gear scary.
With a 360 the scary goes to 80 mph and maybe a bit more, depending on the chassis,lol.

You know how when you torque the lugnuts on your car, you use a breaker bar about 18 inches long and just lean on it a lil to get the footpounds you need? Well imagine your bar was just 70% as long. You would have to jump on it to get the torque into the ballpark.
That's like the difference between a 360 to a 318.
>With a 318 you're always jumping on the throttle to getchit done. Whereas with a 360 yur just rolling into it.
>a 360 is a lil over 12% bigger, so right off the hop your 318 needs 12% more rear gear just to try and hang with the 360
> but the 360 makes more torque, and makes it earlier, so the 318 needs more stall as well.

You can flip these around as well.
Say you had a 318 with a 3200 stall and 3.91s.That could be a peppy combo, but obviously would not be fun on a long commute and would burn thru gas in a hurry. Swapping in a 360 would let you ditch the 3.91s for 3.44s, and ditch the 3200 for a 2400.You would be hard pressed to notice a difference in the zero to 60mph contest, and obviously 3.44s are gonna be more hiway friendly.

Now; as to swapping out the automatic. The 318 needs the Torque Convertor, because of the hydraulic Torque Multiplying feature it brings to the combo. The internal ratio can be as high as 1.8 or more, which basically makes it a two-speed, infinitely variable between about 1.1 and 1.8, power multiplier. The multiplier automatically varies by the torque differential across it and that means it also varies with roadspeed.
The bottom line is, that your 3-speed automatic, actually has one lower gear ratio than you think. The acyual 904 ratios are 2.45-1.45-1.00.. But with the TC included,you can so sorta think of it as 4.41-3.43-1.79-.90-1.00
the black is the first gear spread, the blue is second gear,and green is third gear. The red is at zero slip which can be achieved only while cruising, and only under certain circumstances, or with a loc-up TC. So count 'em up; I get 5 ratios out of 3 gears.

Your 4-speed comes in three verities, the most common is
2.66-1.92-1.40-1.00 compare that to your 904
4.41-3.43-1.79-0.90-1.00
You see what happened there?
But don't despair quite yet.
Your stock LA smoggerteen might make 200ftlbs at 1800stall, so when you floor it,with 3.55s, at zero mph, she might put down 3130 ftlbs into the rear axles, which is enough to break the tires loose. When it does the TC ratio will drop back and your ftlbs might drop to as low as 2260 usually not enough to sustain the spin thru the entire first gear
Now lets look at the 360LA.b 300 ftlbs @2000 so it will put out 2830 ftlbs at zero mph, also enough to break traction. It has no TC to mess it up, and because the tires are already spinning and because it is 12% bigger thab the 318 with vastly more inherent torque, it will continue to spin all the way thru first gear. yes even the stock low-compression job.
But here's the deal ....... you could continue with the A904 and say 2.94s to put down 300ftlbs into that 4.41 starter gear , and put 3850 ftlbs into the rear axles, plenty to break traction. And when the TC rolls back to say 1.4, still have 3030 left at the top of first gear, not even considering the fact that the 360 is gonna make way more than 300 on it's way thru the torque peak.
You see what just happened there?
It's really really hard for a stick car to be as quick on the street as an automatic car, with the same engine and rear gear, and the auto having a decent stall. And you can thank the variable ratio Torque Convertor for that.
There is one problem;
the 360, when warmed up a lil with decent compression, actually makes waaaaay more bottom end torque than your street chassis/street tires, can handle. And if all you can fit is 255s you are in for a scary ride.
But if I remember, that is what you wanted,right? lol.
To tame a hot 360 you will need at least 275s in straight ahead work, and 295s for stability and predictability in the power-turns; remember when sliding sideways, the rear brakes don't work, and the car will pivot around on the front tires....... unless you lock them up, and then you are in an uncontrollable spin . So do yourself a favor and fit the biggest widest front tires on your car, that you can, and learn the fine art of braking....
which with a clutch, is a nightmare; on account of
A) you don't have 3 feet, and
B) your 360 will have way more power than your rear brakes do, so braking and gassing and steering is gonna get exciting, which is what you wanted tho, right? lol.
So bottom line is this;
between a 318 and a 360, it's not even a comparison.
Now; IMO, the 340 has a better balance of street torque than either of these. It has lots more than a 318, but doesn't overwhelm the tires like a 360 does. In srcond gear, with same gearage, I'd rather have the 360 but only because the Hot360 is capable of spinning the tires right thru second gear to 60,70, and even 80 miles per hour .... with 3.55s. You wanted scary right? Try riding that slippery beast to 80 with the rear end wagging around.
Well; yur stock 8/1 360 with iron heads might not hit 80 and still spinning, in Boise Idaho/elevation 2700ft. Noooo, yur gonna need pistons,lol, and some small closed-chambers and 180 psi cylinder pressure. Oh well, it was fun talking about it,lol.
I tell you what tho, if you kept the 904 and upped the stall to 2800 and reused your 3.23s, then, the money you save right there is just about enough for both pistons, a zero-deck, and aluminum closed chamber heads right? You wanted scary? right?
You can get scary with any SBM. It just takes a lil more gear with the smaller ones and the scary doesn't last quite as long. With a 318 you gotchur first gear scary. With a 340 you get second gear scary. With a 360 the scary goes to 80 mph and maybe a bit more, depending on the chassis,lol.



Oh boy, 8yr old thread! I gotta pay more attention!