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alex
alex HalfDork
9/18/09 12:45 p.m.

My dad got the title to an '85 GMC 1500 from a client. Rough, but it could be mine. I know very little about this truck, and haven't seen it in person yet. Questions:

It's a 'High Sierra' model. Does that have any distinctions beyond a trim package or paint? 4wd? Engine/transmission/gearing changes? Anything?

Can anyone counsel me (via PM or email) on how to hot-wire the thing? The keys are long gone.

Where do the goofball owners of these things hide? You know, the ones who make them into pre-runners...

Bobzilla
Bobzilla HalfDork
9/18/09 12:51 p.m.

www.fullsizechevy.com Great source of info. "High Sierra" is a trim package. With the GM (and all older domestic trucks) the engine/gears/trans/diff's/transfercases are wide open. If you find the little sticckerwith the 3 digits option codes any GM dealer can tell you what came inthe truck originally.

alex
alex HalfDork
9/18/09 12:57 p.m.

Thanks 'zilla. Do you happen to know where that option code sticker might be found?

Thinking out loud: would this be a good home for my 460 Ford motor? That has the potential to piss off both camps...

914Driver
914Driver SuperDork
9/18/09 1:40 p.m.

I had an '86, I think the options code is inside the glove box.

Here's what it all means:

http://chuckschevytruckpages.com/rpo_codes_1973-87.html

alex
alex HalfDork
9/18/09 1:46 p.m.

Nice. Very helpful link.

ClemSparks
ClemSparks SuperDork
9/18/09 2:14 p.m.

I can't really help you too much, but I jst picked up a '77 Chevrolet (2wd, short wheelbase) the other day.

I've found www.67-72chevytrucks.com to be a pretty good resource for the '73-'87 body style (They have subsections for all generations of chevy trucks...)

I don't know if there'll be any prerunner specific stuff, but it wouldn't surprise me.

A 460 would certainly motivate it. The one in my F350 (that I traded off to get the chevy) had CRAZY torkz!yo.

Clem

alex
alex HalfDork
9/18/09 2:32 p.m.

Since I haven't seen it, and therefore reality hasn't yet reared its ugly head, I can't decide between prerunner or street monster. Either way I'm seriously thinking (in a daydream sense) about that 460 swap. It's just so wrong it's right. I'm building mine just with headers, an RV cam, and flowed/ported iron heads, and it should still be a tire shredder.

Mean time, anybody have advice on the hot wire? I need to see if this thing even runs - I heard rumors of a bad fuel pump.

ClemSparks
ClemSparks SuperDork
9/18/09 2:38 p.m.

I'd have to look closer at an HEI and try it out...BUT:

Basically, you need to get power to the coil (one of the ~3 wires going into an HEI) [actually...an '84 might have more wires and computer controlled carb...but it should still work].

Once you have power to the coil, use a screwdriver or other method to "jump" the positive terminal on the starter to the trigger wire on the solenoid.

That's one way to do it...until you replace the ignition key switch.

Clem

triumphcorvair
triumphcorvair New Reader
9/18/09 4:34 p.m.

I have a stock 84 3/4 ton GMC with a 350 thats been my daily driver now for 5 years. It ain't pretty but its never let me down or on the side of the road. No problem with finding parts either. Mine's carburated, not sure when they went to EFI.

tuna55
tuna55 Reader
9/18/09 5:19 p.m.

Am I the only guy thinking that that doesn't constitute old?

stuart in mn
stuart in mn SuperDork
9/18/09 6:44 p.m.
tuna55 wrote: Am I the only guy thinking that that doesn't constitute old?

Yeah, I was thinking 50s or maybe 60s when I saw the title.

914Driver
914Driver SuperDork
9/18/09 7:08 p.m.
alex wrote: Since I haven't seen it, and therefore reality hasn't yet reared its ugly head, I can't decide between prerunner or street monster.

What do you want to do with it?

Driver, tower, beater, prerunner? That would make a difference. They're nice trucks, I towed the BatVan down with one. Snot, personable, all the right sounds. Strong. Pick a niche, as usual rust is the enemy.

Free is good but do a good undercarriage exam. Bad? Flip it.

Dan

Dan

hotrodlarry
hotrodlarry Reader
9/18/09 7:59 p.m.
triumphcorvair wrote: I have a stock 84 3/4 ton GMC with a 350 thats been my daily driver now for 5 years. It ain't pretty but its never let me down or on the side of the road. No problem with finding parts either. Mine's carburated, not sure when they went to EFI.

1987.. most full size trucks had the TBI from then on.

dj06482
dj06482 New Reader
9/18/09 8:46 p.m.

87 was the first year of EFI, I believe...

curtis73
curtis73 HalfDork
9/19/09 6:32 p.m.

yup... 87. that's also when they went to 1-piece rear mains. Early 85 would have had an 800 cfm Qjet. Extremely late 85s started using the electric Qjet which is fine, but doesn't really support modifications.

porksboy
porksboy Dork
9/20/09 11:19 a.m.

What year did Chevy move to port injection away from Thottle Body Injection? I know 94 had the Throttle Body. I ask because I have a line on a 96~97 Tahoe.

curtis73
curtis73 HalfDork
9/20/09 4:20 p.m.

TBI was 87-95. 96 Vortec stepped up to MPI, but the TBI stayed in production on medium duty chassis up to at least 2000.

Full size cars used Qjets through 87. Then a mix of TBI and Qjet until 89, up until 94 when they went to the LT1/L99.

A/G bodies used Qjets until they died in 88.

F/Y bodies used Qjets up until cross ram and TPI, then kept that until the LT1 years.

porksboy
porksboy Dork
9/20/09 6:57 p.m.

Sooo, what would a 96 Tahoe have?

Strizzo
Strizzo SuperDork
9/20/09 9:21 p.m.

Mpi

alex
alex Dork
10/11/09 11:42 a.m.

Reviving an old thread of mine: I picked up an '88 GMC 1500 Sierra yesterday: 305 TBI, 2WD, auto, regular cab, long bed, with a sweet A.R.E. utility bed shell. The 305 seems healthy, but a little breathless. What's the recipe for reliable power from this lump?

I've heard these things respond to shocks/swaybars. Where does one locate such things?

Pictures soon (like you need to see another GM pickup).

Stealthtercel
Stealthtercel New Reader
10/11/09 3:23 p.m.

Both of Alex's questions can be answered by Car Craft and/or Chevy High Performance. Seek and ye shall find. The answer to the question "How can I get power from a 305?" does not HAVE to be "Trade it for a 350."

patgizz
patgizz Dork
10/11/09 4:07 p.m.

but the best way is indeed - swap in a 350.

my TBI trucks responded very well to full length headers. nothing else was worth doing.

Bobzilla
Bobzilla HalfDork
10/12/09 11:32 a.m.

Open element air cleaner, TB spacer, injector spacer, headers and a 3" single exhaust. It'll never be a rev happy beast, but it will pull down low like nothing on the street today that's not blown.

ultraclyde
ultraclyde New Reader
10/12/09 11:53 a.m.

I have a set of z28 305 heads (small chamber, new springs) just laying around my shop. PM if interested. I was going to put them on my 350, but the compression would have been like 12-to-1 or something

alex
alex Dork
10/13/09 7:14 p.m.

All right guys, be gentle with me. I'm new to this SBC bidness.

Bobzilla, can you recommend sources for said parts? I like low down torques. Any idea what I might expect out of your setup?

Ultraclyde, I don't know how 12:1 compression on a 350 relates to my 305. And, I assume the Z28 heads are desirable for my application...?

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