New Brushless buggy

Ok, so a little more research. Looks like same spur gears as gasser but the pinions have a different bore?

I think you are going to have to ask yourself what you are going to be doing with it to answer the diff oil question. The thicker the diff oil the more the diff acts like a posi-traction rear end. The silly putty deal effectively locks the diff (better for on road racing than off road). Someone will be along to correct me if I'm wrong or provide more in-depth explanation.

I do understand how it works, just not familiar with the particular vehicle and how it reacts to different weights. Like I said, this will just be used for bashing, mainly on grass and loose dirt, no racing and no asphalt. Just trying to get a basic starting weight to put in the diffs before I even run it. I plan on doing a complete tear down before running it so I can check everything over.

A little back story, I haven't really had an RC for quite a few years. I started with a Duratrax nitro evader which I had an absolute blast with. However, my offroad club (full size) was running our rc's at a Monster Jam event as an exhibition deal. Well, my entire car and tool/parts bag was stolen from a locker room while we were doing the rest of the event. (I did take first place in the tough truck competition with my full size offroad truck if you can consider that any consolation) I had the car for quite a while, tons of spares, including just about every tire you could get (all on rims) extra bodies, basically every hop up you could imagine for the car, a ported OS .18 cv-r motor, etc. So tons of money in the thing, I was super pissed and just never really got back into it since basically everything I had for rc was gone. This was quite a few years ago and I am basically starting over from scratch. I ordered the car, all new lipos, new charger, etc, etc. That is why I am trying to figure out what kind of stuff I am going to need for this car. I no longer have a stash of diff oils, shock oils, anything.

I did just order a 1L bottle of 40w fork oil (motorcycle stuff) for the shocks, seems to be a good place to start for that (Rocky mountain ATV/MC actually had some) as long as they are the same as the HPI's. That seems to be what is the original stuff for that (thickest fork oil you can get)
And a set of knobby tires as the originals are just the same pin style as the original baja which everyone says are completely worthless.
I also ordered the hobbywing esc programmer so I can tweak that if necessary.

I did have a Redcat rockslide RS10 for a little bit, but it was one of the really early ones and it just wasn't really my thing. I like to go fast. I also bought my 6yo son a losi 1/18 desert truck a little bit ago, but I haven't done anything with it really, they aren't very fast, really don't break and he is just learning throttle control, steering, etc. Now my 8yo daughter wants one, so I think I am going to get the Redcat Volcano 18 V2 as she wants to run over stuff and they seem like a pretty good deal for the performance.

Houston we have a problem....

Just showed up and initial testing the 2 gensacearespammers 4s will not fit in the tray. The tray tapers toward the bottom and they will not sit next to each other. I have never used lipos, are they all hard cased like these or is that the problem? The lipos have Deans style plugs and the esc has xt150's so I am going to have to order an adapter to even try it out. I really want to make sure the esc and motor work before tearing it apart.

I tend to run normal soft packs as the hardcase packs do tend to be larger and less flexible to fit in battery boxes, Just make sure there very secure and no chance of getting punctured if you get hit by another car.

Well I changed some connectors, barely got my 4s cells to fit with the battery cover on, took it out and within 5 minutes I broke the steering servo horn. No big deal, ordered an aluminum one from KM. Got that on and I crashed into my boat trailer (really hard crash) and snapped a ball off of one of the steering arms, not the plastic but sheared the metal ball right off. Got that fixed and put my new rear tires on finally. Holy crap is this thing stupid fast! I started rolling it end over end, crashed a few times now and nothing else has broken. Actually super tough, way better than I thought it would be. I did blow a tire completely off the rim and disintegrate a tire foam but that was probably bad assembly on my part. Super happy with it so far.

What batteries would folks recommend?