He's running a 96, so that should be external balance or am I backwards????

 

SO your saying i need to get the motor balanced when finished who does this stuff

 

It depends how you go at it. If you get a 4.2 shortblock or longblock and toss it in then no. But if you tear into your motor and replace your 3.8 crank with a 4.2 crank then yes. A local machine shop for engine blocks can do this for you. I think NAPA also does it.

 

No it's not like balancing and blueprinting a rotating assembly. IT how the crankshaft is counterbalanced that matters. You have to use a neutral crank, with a neutral pulley and flywheel, and an external balance crank with an external balance flywheel and crank pulley.

 

ok you guys are confusing me now lol tell me what i would need for this to work lol and what i would need to do

 

You're engine is externally balanced. You have to use a 4.2 short/longblock that is also externally balanced, that's all. Just make sure your crank pulleys are the same on the new engine as it is on your 3.8.

 

http://www.3.8mustang.com/forum/showthread.php?t=92629
Go read, it will answer all your questions. come back if you have any.