Since you will be keeping the 2 speed and mech brakes and 3s lipo, may I suggest a feigao 8l. It will allow decent speed, 35mph plus, with normal gearing. 40/16 gearing will be fine and will most likely run cooler than the 7xl. The 8l with 3s will turn faster than the 7xl, and the mm will most likely see a lower amp draw with the 8l. Because you would have to gear the 7xl higher you place more load on it, causing a higher amp draw. I have personal experience with the 8l on 3s lipo in a revo, and it ran fine with good temps. plus it is 10 bucks cheaper. It will also be wise to run a ubec, it will help the mm temps.

i was going to run a ubec. but will the 8l be as quick as the 7xl? i mean will it have the same acceleration and everything as the 7xl? and a 16/40 is way different from stock. stock is 18/38. but wit ha 16/40 it will still do around 35? will it be able to handle 4s once i step up to that?

You will not find a motor that will work well on 3s and 4s. You want the motor speed of a feigao to be around 35k rpm. Much more and it will get too hot. Much less and your gearing will be too high and the motor will heat up due to increaded load. The 8l will easily pull wheelies, and we geared it for 40 mph and it ran fine, just a little warmer than the 40/16 gearing. On 4s the 7xl will be a beast, but 3s will not spin the motor fast enough.

well i plan on using a 4s later on. 3s for right now. and later on down the road it will be 4s and 3s. so easy wheelies and close to 40mph with the 8l on 3s. and on 4s its useless? so i wont need to drop the money into twim 2s packs. and it will still be a nitro killer... hmm... i kept hearing that a 7xl will be good on 3s though. i know tekno used a neu rated for 2500 kv and a 3s with the mamba and in the videos it looks like amazing track speeds. good combo of torque and speed. and on 4s it will be an awsome basher. if an 8l will have as much or more acceleration and slightly higher speeds on 3s, it will be good. but id like to be able to run the crazy voltage and have a serious basher

Well for 60 bucks it is cheaper to buy another feigao than a 4s pack. Try the 8l out, you can always sell it. They usually fetch 40 buck or more used.

and your saying 35-40mph with wheelies easily? and then if i did want to step up i could go to something like a 9 or 10l and be safe on 4s?

If you keep the 2 speed and mech brakes I do not see a problem running a 10l on 4s. The 7xl will provide more power than the 10l will on 4s. However the 7xl will require better batteries than the 10l will. It is a balancing act picking a motor, you need to take into consideration the battery and gearing.

What 3s battery do you plan on running?

maxamps 5000 lipo. thats what i will run on 3s right now. and later on i will probly get twin 5000 2s to run in it if i go that high. i already have the 3s. and i will be running 2speed and mech brake. and a 9l is rated for 2700kv(around that) so it would probly run a little cooler, slower, and have more acceleration than the 8l right? or should i just get the 8l? since you say the 7xl wont be able to turn fast enough on a 3s... that disapoints me. squee said he runs a 3s and 7xl and it does good.

Given your battery choice, you may want to stay with the 8l and the 16/40 gearing. Nothing against maxamps, but if you are going to buy a pair of 2s lipos go with the trakpower batteries. I have a pair of 5k maxamps 2s packs and was not happy with their performance oin my 7xl powered revo. Did not have the punch that a battery of that size should. Not sure what squee is using in the way of batteries, but it is most likely a better pack.

The 9l will run cooler, but slower and the acceleration will not be much differnent if any. I have run a 9l in a heavily modified tune buggy stampede. Not a bad motor, but the 8l worked very well in the revo. It runs right at 35k rpm on 3s and will allow for lower gearing than the 9l will. That should help the mm and the batteries.

I think you would be fine with the 7X, personally. If you get the Feigao from United Hobbies, you could get both. There rather cheap there.

well i was actually looking at possibly the reedy packs once they come out. when they get out thats probly when i will get the money for a 4s. okay so 8l, mamba max, and tekno kit. keep the mech brakes and 2 speed and i should have a fast truck? faster than a 3.3? sorry for all the questions im just kinda worried abotu getting something that wont do what i would like it too.

I wouldn't use the Tekno kit. The RC-M mount with the Tekno tray is the way to go...

why? whats wrong with the tekno kit?

i like the idea of it. keep your clutch, mechanical brakes, everything needed is included. seems liek a decent deal to me.

Yea, its a decent deal, but the clutch is the reason I wouldn't get it...