i have a 89 chevy k1500 with the 4.3 v6 and manual trans.it is making a loud popping nosie in gears 1-3 not in 4th or 5th.i have got under the truck and check my u joints rear are good.the front had a bad one so i pulled the front drive shaft just to see if that did it.im really lost right now and dont want to start removing parts that i dont have to. any help is tia.edit the speeometer dosnt work either

 

How about the tranny mount?....check all the bell housing bolts also

 

trans mount looks good.i check the bellhosing.