read your questions, they're ridiculous.
so are your facts.
320, 325, 4 cylinder, 6 cylinder, automatic, manual, whats the difference right.
GET YOUR FACTS STRAIGHT. If the transmission is missing it's flywheel, etc, then look in the F00king cabin to see if it has a stick shift or a thing with P/R/N/D on it
If there is no cabin, look at the thing sticking out the transmission itself. Does it shift like a 5-speed or only up & down like an automatic. Ask someone. USE YOUR HEAD. If you can't remember anything, use some paper and a pen.
What car it came off doesn't even matter now, since it works on your car. But now you're asking about ratio?? Clean the yellow sticker on the diff, it will say the ratio on it as I previously posted. Oh right, you don't read previous posts.
No driving at 4k rpm (vs 3k) will not kill your engine. Technically it will put more "wear" on it, but "technically" a well lubricated motor will sustain no damage once it has warmed up. At the same time if you have more power at low speeds, you won't have to rev as high on the street. What do you think is better for a engine, continuous 4,000 rpms, or erratic redlining. As long as you do your oil changes it will be fine. Over the course of a decade, I don't know. In a more realistic context, it will be fine.
I had a 2002, without the 5-speed swaps they're like humming birds anything above 55mph. Didn't stop me from doing 100 all the time. If in 5 years you still have the car and the engine needs to be rebuilt, then so be it. It's not like it's cheaper to be playing around with diffs or buying bigger wheels. You might waste some mpg on the highway, but save it on the street. Just don't be anal. Don't listen to conventional wisdow, or some redneck telling you "son, you're going to blow your engine". That's all outdated nonsense. How many people have you heard blowing their engines? They might overheat it, and throw it out because it got damaged or blew the headgasket, they might run into a tree, need a new transmission, whatever. In much of Europe people drive 100mph in the left lane with their VW Polos, much faster in Germany, and here you're afraid of the effects of going the speed limit. Don't be afraid to rev a BMW. And if you have a 4 cylinder and don't rev it... well that's no way to live.
