My 1/10 truck needs a better servo so I am thinking of taking the hitec 645mg from the 1/8 buggy and using it.

What do I put in the buggy in its place? I am using 6volt reciever packs.

No opinions of sservos here?

if you're taking the servo off your 1/8th buggy steering, replacing it with anything between 12kg-18kg with 0.13-0.15s would be good enough.

if you're taking the servo off your 1/8th throttle, replacing it with anything between 12kg-20kg(or higher depending on your brake abuse) 0.7-0.13s would be good enough.

I know it's odd that the higher torque is for throttle but lately i've seen and heard of many throttle servos dying before the steering servos.

From the other thread:
the preference so far where i am are:
Hitec TGs (I have not tried that but they offer the 7940 which is great, 13kg with 0.07s)
Futaba BLS (I have the BLS-452 for my steering but would have taken BLS-351 or BLS-352, both out of stock here, they are really smooth, quiet and servo horns fits perfectly)
Savox S-1256-S1258 (I have the S-1258, a bit loud and rough but response is fantastic)

A lot depends on how much money you're willing to spend on the replacement. The cheapest would probably be to get the same HS-645MG you had:
http://www.overdriverc.com/proddetai...C32645S&cat=26
But if you want to upgrade you can't go wrong with these:
http://www.overdriverc.com/proddetai...C32985S&cat=26
or these:
http://www.overdriverc.com/proddetai...C37955S&cat=26
And if you want the top of the line, these are the high voltage from JR:
http://www.overdriverc.com/proddetai...9100HVT&cat=26

The hitec 985 seems like it is quite a bit quicker than what i have and more torque also. It seems like a good one for the money

that 645 is going to be painfully slow in your 1/10 steering. it's a torque servo, not speed.

I will have to look at the specs of the servo in the truck. It is the "standard" futaba that came with a magnum junior a long time ago. I know my dad has a futaba s 9304 in his that is much better than mine and it is .22 sec at 6v.

edit
What would you get for the truck?

nothing slower than a .15 transit speed or you may not be able to recover from a slide without looping. An HS-625MG would work far better IMO for steering a 1/10 truck.
Once you try a faster servo you'll never want to go back...

HS-985MG is an excellent servo for the money; yes, the HS-625MG is cheaper but the specs aren't even close to those of 985. 0.13 sec is plenty quick for response time and 172.2 oz/in is more than ample torque for the application.
http://www.overdriverc.com/proddetai...C32985S&cat=26