Author Topic: My '78 Sierra Grande - Big Red!  (Read 15599 times)

Offline Mudder96

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My '78 Sierra Grande - Big Red!
« on: February 02, 2015, 09:04:10 pm »
Picked up this 1978 Sierra Grande on Friday for $1800!











350 w/ Holley 2bbl
TH350
NP203

As of right now, the mods are:

Headers
Dual exhaust (with H pipe)
Two glasspacks and turndowns
6" Rough Country lift
Autogage 8k RPM tach
Autogage oil pressure gauge
Autogage temp gauge
American Racing wheels (AR62 Outlaw II 15x7) with 32" Regul A/T tires
Two Hella lights up front

Issues:
A 2 barrel, really? (With which I'm somehow getting about 5mpg at the moment, might I add)
Fuel gauge stuck at Full (ground?)
No radio
Sticky windows

So really just little stuff for issues!

Has seats from an unknown newer vehicle, gonna see if I can get the seats from my '95 Sierra to fit with a bracket modification.

Not really sure what my plans are for now. First thing is removing the mud flaps, adding manual locking front hubs (all time 4WD ewww), possibly do the Mile Marker transfer case mod sometime as well. Fix the little stuff and then I'm thinking of swapping a 5.3/4L60E or build the carb'd 350 and get a pro built 700R4....all in time though.

On my way home I stopped at a gas station (of course) and started talking to a guy with an El Camino. He had an Edelbrock EPS 2701 intake sitting in the back so I asked him about it and he sold it to me for $20. Says it may have a crack in a coolant passage, I'm gonna look into it but I cleaned it up and it looks nice!
« Last Edit: February 02, 2015, 09:06:28 pm by Mudder96 »

Offline LTZ C20

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Re: My '78 Sierra Grande - Big Red!
« Reply #1 on: February 02, 2015, 09:24:47 pm »
Nice truck! Welcome to the site.
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Offline Irish_Alley

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Re: My '78 Sierra Grande - Big Red!
« Reply #2 on: February 02, 2015, 09:44:18 pm »
welcome from maryland
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Jason S

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Re: My '78 Sierra Grande - Big Red!
« Reply #3 on: February 02, 2015, 10:34:03 pm »
Howdy and welcome from Kansas!
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"

Offline audrima

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Re: My '78 Sierra Grande - Big Red!
« Reply #4 on: February 03, 2015, 12:32:08 am »
Welcome from wv, vary nice truck!



Mariah

Offline illinoisk30

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Re: My '78 Sierra Grande - Big Red!
« Reply #5 on: February 03, 2015, 05:03:58 am »
Welcome from Northern Illinois. Nice find, good price.
1977 Chevy K10 LWB Supercharged 406 TH350
1977 Chevy K30 DRW 400 TH400
1978 GMC K35 SRW 454 TH400
1979 GMC K35 SRW 400 TH400
1980 Chevy K30 SRW 350 SM465

Offline Irish_Alley

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Re: My '78 Sierra Grande - Big Red!
« Reply #6 on: February 03, 2015, 05:08:12 am »
About 5 mpgs that's not right might need a tune up but something that's not lifted and running 38s should see at least 10. The 88-98 seats are about 6" shorter than ours so 3" smaller on each side you will notice it
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Shifty

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Re: My '78 Sierra Grande - Big Red!
« Reply #7 on: February 03, 2015, 09:47:42 am »
Fine truck!  Enjoy!  8)
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

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Offline Mudder96

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Re: My '78 Sierra Grande - Big Red!
« Reply #8 on: February 03, 2015, 04:44:05 pm »
About 5 mpgs that's not right might need a tune up but something that's not lifted and running 38s should see at least 10. The 88-98 seats are about 6" shorter than ours so 3" smaller on each side you will notice it

Yeah I didn't think a two barrel would run rich enough for 5mpg. Do you think adjusting the idle screws could fix the rich issue? It idles at around 900-1000 which seems high for an old carb truck. Usually around 650 or 700 right?

Offline zieg85

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Re: My '78 Sierra Grande - Big Red!
« Reply #9 on: February 03, 2015, 04:51:10 pm »
Proper adjustment will help, timing is crucial as well.  A 2bbl can actually help in mpg if you have a heavy foot but the drag of big tires and the aerodynamics of a brick is all going against you...
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
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Offline cali6shooter

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Re: My '78 Sierra Grande - Big Red!
« Reply #10 on: February 03, 2015, 05:50:48 pm »
Hahah zieg85 that was great bricks are slick man haha my 80 c10 is having timing / mpg issues to

Offline Mudder96

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Re: My '78 Sierra Grande - Big Red!
« Reply #11 on: February 03, 2015, 09:43:20 pm »
Which do you guys think would be the all around best option?

5.3, some bolt on mods, possibly something big in the future
Performabuilt 4L60E
35's on 15x12 wheels
4.11's

or

Mild build 383 Stroker (cam, springs, rockers, headers, etc.)
Built 700R4
35's on 15x12 wheels
4.11's

Also, what do you guys think of these LED headlights? I think the red would look pretty mean at night!
http://www.ebay.com/itm/331287670604?_trksid=p2055119.m1438.l2648&ssPageName=STRK%3AMEBIDX%3AIT

Offline Irish_Alley

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Re: My '78 Sierra Grande - Big Red!
« Reply #12 on: February 03, 2015, 10:37:51 pm »
can you do a stick? granted you lose the od and between the 4l60e and 700r4 i would go with the 4l60e just because its computer controlled and they tend to be a little tougher imo.

 my 79 with 6"+3" of lift and 38x16x16 was getting 8mpgs or so switch to 37.5x12.5x16.5 and it got 10
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Mudder96

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Re: My '78 Sierra Grande - Big Red!
« Reply #13 on: February 03, 2015, 11:09:00 pm »
Yeah I could definitely swap it but I'd do an nv4500 if I could swap it so I can keep the overdrive

Offline Mudder96

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Re: My '78 Sierra Grande - Big Red!
« Reply #14 on: February 05, 2015, 07:20:45 pm »
Well I got rid of the mud flaps, it looks way better I think!
















And here's the intake I got for $20, all cleaned up now!