I have just built a 6.0L for my truck and am fixing to start rebuild/beefing up my transmission. My dad says that before I spend all of the money on the transmission I should see if the motor is even going to run. So I was wondering, if i reinstall the motor, could i just see if it would run without having the transmission bolted up? Is it possible or could I risk damaging something?

 

you can start it, but I would not "free rev" it wthout any load. you will be asking for problems IMO.

 

ive tried it and no it will not start with the plug in's for the tranny unplugged

 

other than a few codes because the transmission is missing it can be done. Just not somthing I would do to be honest.

 

yeah you will have to bypass the nutral saftey switch.

 

same here. made a jumper wire and fired right up.

 

So how exactly do you go about doing that?

 

Didn't have to do that, and I've done it just last month. My 5.3 started right up. You may see a few trans codes, but that's it. The motor will seem to run funny without any load from the tranny not being attached, but it should start.

As for free revs, I feather-footed mine VERY lightly. To each his own... but I had no problems. Just plugged my trans lines, and all was fine.