i am trying to work up some money for a big block engine to put in my jato 3.3 as well as all the parts. what engine has the torque or rpm. i really dont want to loose speed. what is the best engine overall?

junk the jato and get a gt2

Out of all the engines you listed the only two I would get are the O.S 21 tm and O.S 18 tz. All the rest are not direct bolt ins, meaning you need to either modify your engine mount and some how make more room for the new big block or purchase the Newera big block conversion kit. The Jato is a light weight 2 wheel drive truck that really does not need all the extra torque of a big block motor, those motors work better with heavier 4 wheel drive trucks. The smaller motors are lighter and are able to rev out to a higher rpm you just need to have enough displacement to pull the weight of your Jato. Most people are saying the O.S 21 tm is very powerful and are happy with it, my vote would go for that one if your looking for the most power and speed with less hassle. Watch your slipper clutch, that much power will be hard on your tranny.

the tz is basicly a direct bolt in even the tz eb modded...i have one... you put the engine spacer on top of the motor instead of under. doesnt sound like much of a mod to me. havent blown a dif yet b/c of the motor only b/c of the integy shock tower

I just ordered a 3.3 jato for my son and we plan yank out the 3.3 & install the new era big block conversion chassis and install a Nova Mega Big Block .15
This Engine was for the serpent 235 Impact onroad Car and Rips harder then a 3.3 but is only a .15 but a Big Block. Sounds like it should rip but the proof will be in the pudding still waitnig for a few parts in the mail.

lol, wanna send me that 3.3. also how much more power dose that .15 have than a tz.18. im lookin for a new motor