I have the stock 427 and really enjoy it. I also have the LRP .28 Spec 3 you hear many people talk about and it is a great motor for a great price.
http://www.amainhobbies.com/product_info.php/cPath/1_23_79/products_id/29252
You could try a Picco .28 P3. I hear they are really good too, I've just never tried one.
A friend of mine runs the Dynamite .28 platinum. Its good about same power as LRP but costs more.
You could even run the Axial .32 but fuel mileage wont be as good I don't think. If it was me I would go with the LRP since it is $20 more than the stock 427!
Happy Hunting!!!
I have run the 427 and the LRP .28 Spec 3 in mine. I enjoy both very much. The LRP has more power than the 427 and holds a tune better for me.
http://www.amainhobbies.com/product_info.php/cPath/1_23_79/products_id/29252
You could try a Picco P3 .28 I hear they are good, I've just never tried one.
My friend runs a Dynamite .28 Platinum in his. It's a hot motor also but costs more than the LRP for whatever reason.
Than there is the Axial .28 or .32. I know a lot of guys run the .32 in their savage and really dig them. I'm sure its fuel mileage is a little less than the LRP but should have more off the line torque.
Don't get me wrong though. The stock 427 can wheel stand an LST just fine so anything above is just more bang for the buck.
I would probably suggest the LRP since it is $20 more than 427 but iIm sure you be happy with whatever you choose.