And as if that wasn't enough
for a streeter, with an automatic
A stout SBM is gonna have the potential to spin the tires all or most all the way thru first gear. So the starter gear is not thaaat critical. Now it's all about second gear and the cruise rpm. I like to optimize 2nd to just break the tires loose at 32mph, with a footstomp and a DP carb; that's how I roll. I can always back out of the throttle once the car is accelerating,lol.
So that requires careful planning in the engine package. If you don't have enough power, then you have to do it with other means like; Torque Multiplication,Hi-stall,and co-ordinating the compression ratio to the camshaft.
In the world of Mopar autos,we are sorta stuck with 3-speeds, so there is only so much you can do with gearing, and that leads to the hi-stalls; which then allow bigger cams, and higher operating rpms, and before you can say jumpingJackFlash you gotcherself a racecar and are speeding, and are screaming down the hiway at 3500 rpm.
So the simple solution is to just have more power at a lower rpm. Then you wouldn't need the hi-stall, nor the TM, nor the big cam, nor the overdrive, and things start to become real-world affordable.
So then we have a battle between:
Plan-A) a small engine with hi compression to use a high-rpm cam, then the big rear gears and a fairly hi-stall, and finally, to actually put miles on this now mega-dollar powertrain, add the overdrive. So the cost of all this becomes outrageous. and
Plan-B) a bigger engine, and none of those other costs
The thing is, it costs about the same either way you do it, cuz strokers ain't cheap. And strokers have a different problem, and that is finding traction. So then you end up fighting that battle.
But there is a happy medium. About 1 cubic inch per pound of ready to run weight. If you and your car weigh 3200 pounds, then a 318 will be enough to have fun with. At 3600 you need a 360. If you favor hiway cruizing, move up in cubes about 5%, so you can gear down 5%.
It is always better to have a bit too much, than not enough.
And I favor more stroke than the 3.315 cuz I can run a bit more cam and a bit less gear, saving me money at the pump. But I don't see much point in a 4" arm for a 1.5 gear car. What do I mean by 1.5 gear car? Well, 3.55s and 27s will get you 60= 4000rpm in second gear. Right in the middle of no man's land, 1.5 gears from the start-line. Any warmed up SBM at 1 cube per pound, will spin all the way thru first, so when you shift it at 5500, the Rs drop to 3250 so you are basically pulling from 3520 to 4000, and 5500 could get you a tic over 80mph. You might as well just have a 4000rpm engine with mega torque.
Some day,I would like to try a 3.79 crank, in a 318, for about 370 cubes. Yeah that should be bout right.
And if you make the leap to aluminum heads, then it becomes advisable to also step up to a 360, cuz then you have potential to be creative.
It's hard to make enough compression to optimize a 318 for aluminum heads.
It's easy to get the 360 into the ballpark, and only a few more dollars to optimize it. And once you do that, you have a kick-azz engine. and you can run pretty much any gear, any trans, any cam,any weight, that you want to, depending on the mood of the month,or season. That's what I did, and have never been sorry.....
well except for the 292/108 cam,lol. That combo did NOT like 3.55s; the power arrived at 50mph/5600 mph...... in first gear, and topped out at 60mph/7000rpm. I built it like that on purpose as a 1-gear deal. But I didn't really like the combo when it wasn't floored..... which turned out to be most of the time... go-figure.
But not sorry about spending the money, cuz the very first time you drive that aluminum-headed beast, and feel that 185 to 200 psi, it's like a friggin supercharger..... you'll be forever hooked.
And as if that ain't enough, it burns 87E10 all-day,every-day.........
So; in answer to your question; that depends,lol
