Quick Help with 83' gmc

[RapidRide2]

I have spotted a seemingly really clean 83' gmc 1/2 ton 2wd 8 ft. bed. 305,, 700r-4(in good working order) pwr windows locksA/C. no rust Mississippi 2 owner truck. My questions are does this truck have any type of basic computer for timing or carb solenoids?? If not i guess it would have a regular h.e.i correct??? Does anyone know what gear ratios were available in 83' in 1/2 tons?? When i inspect the truck what are some things to look for on these 83's as far as body and mechanical???? Does anyone know what m.p.g. a decent tune up with the 305 single cab 1/2 ton w/overdrive should get????Thanks a million to all who can help. Matt

[SanitysBane]

allright, my 83 sounds the same as yours minus the pwr doors, my rear end had 2.73s, and no it does not have a regular H.E.I. it has "Eletronic Spark Control" all you have to do, as per my gm shop manual is to unplug the knock sensor and the ESC can't do anything, i've got the factory 305 dizzy, on my 454, and i've had no problems with it. the carb only has 1 or 2 solionods on it, and a ton of vacum lines on it. as far as the body goes, look at the cab corners, and anywere else for rust. hope this helps

[RapidRide2]

Say for instance mine would have 2.73's with the 700 r-4. I have heard that upping the gear ratio 3.42-3.73 (numerically) actually pulls beter mpg's due to having the engine in it's sweet spot when cruising in o.d.versus somewhat lugging down the engine. It somewhat makes sense to me. I guess i would eventually be willing to throw an aluminum street intake with a more "maintenance friendly" aftermarket 600cfm carb with a regular h.e.i.. P.s. Is 83 the only year for e.s.c.???? And yes there is a ton of vacuum lines. I would like to clean that part up for sure. Another question what type of ten bolt rear ends did these trucks. I really like having a lim. slip rearend in a pickup in the winter time. What kind of posi units fit into these rearends??? What size ring gear did these trucks have???

[Destructo]

My 83 GMC has regular ol HEI, and it was comepletely stock, also had no A.I.R from the factory. Mine had a th350 trans and only turned just around 2000 rpm on the highway, I suspect it had 2.73 gears also.

The early 700r4s are known to have weaknesses, so make sure the torque converter locks up and OD works.

You want around a 2000-2200 rpm cruise range on the highway for the best fuel mileage depending on what cam you are running.

[SanitysBane]

i can't really tell u anything about the 305 that came with my truck, it ran for about 30 seconds, had a bad knock, turned out the oil had never been change in it, so the #1 rod bearing had spun and the rest were about to go, no problem, had a 454 sitting in the back that needed a rebuild, i don't know anything about the 10 bolt truck rearends, i do know that they came defaulted from the factory as an open rearend, im shure that their are others on this board that would know more about it.