Either crank is going to have the hotrods connecting rods, if you put good bearings on the crank then it probably doesn't matter that much. I like to run a max load bearing on one end and a TZ bearing on the other. Which one can you get the better deal on? Even billet cranks run hotrods.
I don't think you would feel that much difference since you have a 4mil crank. It does not sound like you are a drag racer so i would give it a try and see if you like it. It is not that hard to swap out domes.
You would need to go down to 160 or below to run 93 octane. You would lose some bottom end grunt on your motor(torque).If you went up from were you are in compression you would lose over-rev on your top end. I like having around 180 compression, think that is right around the sweet spot if you run the fuel that supports that kind of compression. What dome size are you running now?
ATF type F all the way, i don't run it because it is cheap, i run it because it works EXCELLENT, it has grabbing agents in it to keep your clutches from slipping, and does not rob horespower.
The guy before you was running race gas for a reason, if that motor had high compression and advanced timing it would not take long to detonate a motor.
I have a 12 over swinger, 12 paddle extreems with 72 inch rollout. I have 39 pwk alky carbs and 15-42 gearing on my 4 mill cub and love it. Good hole shot and carries the front end. Much shorter of an arm and i would have trouble keeping the front end down when i launch. Stock frame not lightened, front brakes removed.
Are you sure it is gear oil? It could be 2 stoke oil from your pipes not sealing on the flanges on your cylinders, might need to replace the o rings in your pipes were they slide onto the cylinders.
The coils you seen on the studs that came out were your threads. Just put some helicoils in or have some put in if you can't. They are not that hard to put in if you have the kit, but you can screw it up if you don't do it right.
I don't think the piston to cylinder wall clearance is the same from a cast pistion to a forged piston. A stock banshee piston is cast and wiesco is forged. I wouldn't run a forged piston unless it was bored for it. I think the expansion and contraction rates are different between the two pistons, forged and cast.
You lose traction not power. I have a 12 inch arm but have 12 paddle extreems to help get the traction back. Its all in how you have your bike is set up. My front end still comes up but i mainly drag.
Since you have oof pipes you might want to start a little higher on the main and work your way down (330 to 340) i would rather be a little rich to start than lean. Do you have pod filters?