So with all this enjoyable talk about rust and wheels, I never really spec'd out what the long-term build plan is for this truck. So, for your consideration and comment...
BUILD SPEC - July 31, 2019
Overall Goal
The plan is for a stock-plus build of a mild family hunt/fish/camp/adventure rig keeping it true to the mid- to late-'70s. It should be capable in the snow and on state forest roads but still a daily driver and comfortable and safe for longer highway trips.
Current Stats
1978 K10 Suburban Silverado
* New Crate GM 190hp 350 V8 <4000 miles
* Original Q-Jet
* TH350 - no apparent issues
* NP203 - full-time no apparent issues
* 3.73 gears - no apparent issues
* Brakes are new
* 15x6 stock steel wheels with dog dish caps
* Crappy Toyo tires - 235/75/R15s
* Air Conditioning - converted to R134a and working well. Front only.
* Cruise Control - speedo cable bypasses transducer so unknown if it works
* Comfortilt steering wheel
* Tailgate - glass motor works fine
* HD Transmission Oil Cooler
* Factory dual exhaust
* Two-tone paint 71 Metalic Red (Red Poly, later called 'Dark Carmine') 60 Santa Fe Tan
* Red special custom interior
Overall clean inside and out. Drive train seems solid and well maintained with a few suspect things to go through. Interior is overall good with a few bothersome things like cracked/torn piping on the driver's seat and a low front headliner. Body is solid with some decent quality rust repair here and there, but surface scabs popping up in a few places that mean eventually we're gonna need to address rust. Cab mounts rusted out, only inspection failure point.
BUILD PLAN
DRIVE TRIAN
* Engine - New 350, so not much to worry about here. Whoever did the install did a nice job and everything seems right. Runs smooth, if a little mild for such a heavy truck.
Open to suggestions for some performance improvements! Nothing too radical and I like carbs, though I'm still learning about them.
* Transmission - Not going to an OD transmission. Doesn't appeal to me on this truck. The TH350 seems to be doing exactly what it needs to do. Shifts smoothly. Going to do a fluid change.
* Transfer Case - I've decided to stick with the NP203 and not convert to part-time. I do want to get it to someone who knows the 203 case and understands them to go through it and service it if needed. Minimum, I want new 30w oil in it.
* Differentials - pull covers, inspect, fluid change.
* Drive shafts - I have a "cabin boom" at 45-50mph that I'm trying to get rid of. U-joints were my first suspect, so I'm in the process of changing them. We don't have a driveshaft shop anywhere local, so I don't have the opportunity to have the shafts balanced or the double cardan (CV) or slip joints serviced. Hopefully the new U-joints eliminate the boom. It's the only issue in an otherwise nice driving truck. Honestly, if this doesn't do it, I'm open to picking up a new front driveshaft for $250.
* Front end - tie-rod ends, ball joints, bearings, hubs, steering components all seem good. The truck is pretty tight. But I'm persnickety, so I'll eventually be going through all this and replacing most. Any suggestions on mild upgrades?
* Brakes - new shoes, everything looks good and stops like it should. Could stop better. Any suggestions on upgrades here?
* Shocks - no complaints, truck rides like it should. Shocks
look like they've been on there for decades though. I like Bilstein yellows, so the Suburban will eventually be getting a set.
* Springs - quiet and provide a nice ride, so not much to worry about here. I'll replace bushings eventually. Also a zero-rate 1" add-a-leaf for the rear to correct the saggy butt.
* Body mounts - These are on the list to do when the truck goes to the body man for the cab support work. I haven't been able to find a full Suburban
rubber and hardware kit for a '78. LMC has poly, but I prefer the ride of the rubber bushings.
* Wheels/Tires - Here's where I'd like to make an upgrade... I want to run a 31"-32" tire, but the stock 15x6 steelies stop that plan dead. So... 15x8 OE-style steel wheels with stock hub caps or a 16" aftermarket wheel appropriate to the late '70s. Thoughts/suggestions welcome. Wagon wheels? Outlaws? Rallys? My preference is to run the original caps, but tires trump wheels. BF Goodrich All-Terrains for rubber.
EXTERIOR
* Bodywork - The big thing is gonna be rust control/repair and an eventual repaint. I hate the idea of a full re-paint, because part of the charm of these old trucks for me is that
they look like an old truck! But I don't see a way to attack the rust without a full spray considering how oxidized/crazed the original red paint is. I really like the look of the faded/patina'd Metallic Red, but I'm not super keen on it as a newly sprayed color. So while I'm usually a "stock, as-built" kind of guy, I may consider a color change to another GM truck color. The red interior will certainly limit appropriate choices. It'll be a while until I can afford bodywork/paint, so I have time to drive myself crazy thinking about color. Any thoughts?
* Trim - tough to put original dinged-up trim on a freshly painted truck, so I'll probably spring for new shiny bits for whatever parts I can't clean up.
* Rubber - truck could use new weather strip all around. Nothing is leaking horribly, but it's probably worth doing sooner than later.
* Rubber #2 - there IS a leak at the windshield. There's no rust there now, and I want to prevent any from starting. Rubber around windshield looks good and is still soft, but it looks like there are places where it's not seated correctly against the sheet metal. It's definitely a rubber-to-metal seal that's leaking, not rubber-to-glass. Maybe an auto glass place and fix this?
* Lighting - I'd consider a headlight upgrade if I could find an option that truly looks like stock sealed-beams but functions like modern high output headlights. Otherwise, relay upgrade. I need to research this...
* Accessory lights - '70s-style KC Daylighters and fog lights on the front. Looking for a mounting option for the KCs that will let me avoid drilling the bumper.
* Roof rack - a roof rack would be super useful for our family, but I absolutely shudder at the thought of drilling holes in the roof... Ditto a rear spoiler.
* Running boards - I took the aluminum full-length boards off because I'm not keen on how they look, but there's no denying that they protect the lower body from road rash. Maybe decent mud flaps?
INTERIOR
* Seats - Only issue is the piping has cracked and the seam opened on the driver's seat. Foam is a little soft there too. Hoping I can restore it and keep running the original seats.
* Dash - dash has two small cracks in the pad. I couldn't care less at this point. Everything else looks nice and functions as it should.
* Doors - plastic/vinyl needs cleaned up, but everything is pretty nice. Need one window crank handle.
* Headliner - the rigid headliner is low in the front. Hopefully this will just need to be taken down, re-folded, and put back up. While it's down I'll add some Dynamat or similar for thermal and sound insulation.
* Carpet - good enough. I may pull back sections to add products for thermal/sound insulation.
* Floor mats - I need a set and I'm open to suggestions.
* Accessories - I need a place to mount my phone and a charge port. Maybe 12v accessory plugs at the rear seats for the kids and one back to the tailgate. Cup holders were taken care of with an aftermarket bench seat console. If the sound system is ever upgraded, it'll be a stock head unit retrofit with Aurora Designs guts by Gary Tayman... though the radio is pretty low priority. If I could find a vintage aftermarket clock or a compass, that would be neat. Maybe a tach or a vacuum gauge down the road...
* Overall the interior is really pretty nice and I want to do as little as possible. Certainly not a full re-do. Again, part of the charm of these old trucks is that they look like an old truck.
So. There. Now it's all written down.
