Dozer questions

[buzzy16]

So with my tonka dozer conversion I am going to have some questions before I really get in to the build, even though this is going to be a slow build.

I thought one thread for all my questions was better than a different thread everytime I am unsure of something.

So firstly does it matter where the drive sprocket is located, for instance most builds have the motors driving the back sprockets, but can I have one track powered from the back sprocket and the other track from the front one or will that cause problems?

Also I saw on a thread the other day someone mentioned using grease to tension the chain insted of a chain tensioner, how does this work?

For those that have built dozers have you used bearings or just bushing or nothing at all where the drive shafts go through and the idler wheels?

Thanks you in advance any help is greatly apreciated

Buzzy