Just got an '85 5.0 with a wicked balance issue, the tool i bought it from sold the original roller motor and put in a rebuilt 5.0 out of an f-150 that shakes like a bastard at idle, 1400 rpms and becomes unbearable at around 4000 rpms but goes away a couple hundred after that, I didn't know if this was an easily diagnosed issue or if i should just send the motor to a machine shop for a lower end rebuild plus a balance or what. any help would be appreciated, also, anyone who knows of a reputable machine shop in the new england area that will do a lower end job AND blueprint and balance my engine would be kick ass, thanx