Hi, i'm new here, my problem is an 83 gmc 1/2 ton pickup. It had a 305 or 307 when he bought it new, he can't remember, he had it replaced about 92 with a 350, on top of the alternator is a bracket with a black plastic box about 1.5" long by 1" tall by 1" wide, 1 vacuum goes to the carb. 1 vacuum goes to the charcoal cannister, and 1 wire goes to what he calls a converter valve? it has A2103 on top of it. Does anyone know what it'* for. Thanks sooo much for your help. Sadi.

i doubt its a 92, do the valve cover bolts go around the edges or through the middle?

cant help with the emissions, as its not alot of work to bypass those things which is what i always have done.

They go thru the edges, my dad is getting pretty forgetfull, but it seems he
had it replaced about 92, but your probably right about the year it could be
be closer to 96 or so.

They go thru the edges, my dad is getting pretty forgetfull, but it seems he
had it replaced about 92, but your probably right about the year it could be
be closer to 96 or so.

if the bolts go around the edges its before 87.

theres a post with a picture of the 80'* emissions stuff maybe something there will be what you need
http://www.montecarloss.com/communit...&Number=734350

Thanks, we'll check that, the motor was put installed in the mid 90'* but they must have put in a mid 80'*, Thanks again. Sadi.