2 trucks, which to build up and keep?

[cLaWz]

Not having as much as experience as some of you on the board, hopefully I can get some input on which one of these to keep and work on.

A little back history on the 2.

Truck A (C20 in my sig) - 1983 3/4 ton C20 with a near stock 454 (told it had an upgraded cam in it) and a TH400 Automatic Transmission. Original 350 caught fire and upon installing the 454 the PO gutted a lot of the wiring harness in the engine compartment. Body and paint were in great shape until my wife dodged an oncoming car using the exit at our old apartment and met a gate. Rippled a large portion of the bodywork on the passenger side.

Interior - Better on this truck
Body - Paint is better but due to the body damage it's in worse shape.
Electrical - Pieced together engine bay and cab harnesses.
Gas - Don't even get me started with the 454....
Engine - Had to rebuild the top end not long after my wife bought it due to a head gasket letting loose. Runs great after buttoning her back up.
Tranmission - Rough shift from Park to Drive or Reverse, could be the modulator going but haven't worked on it due to a brake issue keeping it parked.












Truck B - 1986 C10, 1 owner with the original 305 and SM465 (I believe) in it. I have nicknamed it the "Dumptruck" because of the stiff clutch pedal and the throw of the shift lever lol. Picked this up because I wanted a manual transmission truck. Upon inspecting it and the test drive, etc everything was in order with no issues. Motor had been drained of fluids after being parked so they were filled upon my arrival to check it out. Put down a deposit while the guy got a copy of the title the following Monday and left the truck at his place. During this time Texas was forecast to get a cold front (yes, you can see where this is going ) and a freeze and the guy assured me that he would drain the water out and such. Seeing as how it was dark and my 5 year old was cranky I agreed and headed home. PO got a copy of the title and I went down to pick it up to find that the radiator had not been drained. The past 2 nights had been in the low to mid 20's in town and even lower out in the country where he was. Immediately found a freeze plug popped but didn't see anything else wrong. Replaced the plug and filled her up just to find another leak.. this time it was my fear.. a crack in the block. At this point I backed out of the deal and asked the guy for my deposit back but he said he had already spent it and since he was out of work he wouldn't have it for a long while... to cut the story short I ended up leaving with the truck for the cost of my deposit and with extra spare parts and a tanneu cover, etc. Not happy that I was pretty much forced into it.

Interior - Very very rough shape. Needs to have seat pulled and everything cleaned. Dash pad appears to be pretty much shot.
Body - Body is in much better shape with only a few minor dings. Paint is terrible due to the original blue wearing thin. PO had a buddy shoot it with a leftover green from another job.. no bodywork or prepwork done.
Electrical - Iffy here as well. Harnesses appear original and complete with some concerning splices for the electronic choke and stereo system. Shouldn't be a hard fix with some time. There is an issue somewhere that it causing the battery to dump if I do not pull a terminal. Believe it is the way the radio is wired but haven't worked on it... not moving right now so not a big deal.
Gas - Unknown, dumped block sealer in it and limped it the 30 miles to my house and it's been sitting ever since.
Motor - Well... cracked block so it's down the tube. Block seal is holding but I do not trust it for much use. PO "promised" to get me a replacement but after being screwed once I doubt it highly.
Tranmission - Tons and tons of clutch and it shifts nice besides the long throw on the shifter which I'm told is normal on the SM465.









This is where I am left at the moment, wondering which one I should focus on and which one I should use for a parts truck. I think the C20 "Big Red" could be less work in the short term since the body work could wait. Dumptruck is rougher around the edges but seems to be the more "complete" truck and is a C10 compared to a C20. Seems parts are easier to get and less expensive plus the 5 lug setup gives me more options for the eventual new wheels. The other consideration is emissions testing. The C20 is exempt here in Texas by the 25 year rule. The C10 will be be next year.

What do you guys think?

[lha1992]

Well, if I were you, I would go with the '83 C20, big red. The body looks better, the truck has all power options for one thing, and the motor runs.

Use the C10 as a parts truck and are the trucks the same wheel base? Because you could instead of repairing the damage on the C20, just flip the beds and repaint the bed to the original color of the C20.

[ont_guy_38]

I would drive truck a for now... take truck b down to the frame and clean it all up , lower it or whatever your going to do then take cab and running gear off of truck and use whatever other parts are better and have a C10 with a big block by that time truck b will be emissions exempt

[cLaWz]

I'm not keeping the 454 in the long run no matter which way I go. Truck is going to be driven to much to be economical with the big block in there. Looking to drop a 350, maybe smaller since we will not be hauling or towing, in it eventually.

lha1992, I have been seriously considering it but what stops me is I really want a manual transmission setup, never have liked auto's. Both trucks have the same hump so theoretically I could convert "Big Red" but not sure how difficult it would be. Still new all this

[ont_guy_38]

c20 with 350 or c10 with 454 probably be about the same of fuel i,m thinking, not saying to keep the 454 but if economy is an issue you might wanna consider the c10

[lha1992]

Originally Posted by cLaWz

I'm not keeping the 454 in the long run no matter which way I go. Truck is going to be driven to much to be economical with the big block in there. Looking to drop a 350, maybe smaller since we will not be hauling or towing, in it eventually.

lha1992, I have been seriously considering it but what stops me is I really want a manual transmission setup, never have liked auto's. Both trucks have the same hump so theoretically I could convert "Big Red" but not sure how difficult it would be. Still new all this

Ahh, okay I see what your saying. I don't think it would be too hard to convery "Big Red" over to a manual, but I'm still new to this stuff too. More than likely go for a 350 in the C20. I'm about to buy a 1972 C30 Cheyenne and having to learn as I go too.

Hopefully, which ever you choose will work out for you.

[tucsonjwt]

Having had 3 square bodies over the years, here is my take on gas mileage:

73 C20 454, TH400, no a/c 10-11 city, 12-13 hwy (very fast truck)

76 C20 350, TH350, A/C 10-11 city, 12-13 hwy (a real dog to drive)

83 C20 454, SM465, A/C, all power acc., gear vendor, 10-11 city, 12-13 hwy (my current vehicle, with a dump hoist)

Your mileage will vary. The only way I see you getting good gas mileage, even with the C10, is with a 6 stick. I have known people with 350 C10s who did not get better than 10 city. Big heavy trucks don't get good gas mileage. I had a 2000 Silverado V6 auto WT which got 18-19 city (driving like your grandma) and a 2003 Sierra Xcab with 5.3 auto which got 17-18 city (driving like your grandma.) (EPA mileage for these vehicles is like 14/17 for these newer trucks.)

Rear axle ratio does make a difference (maybe 2 mpg?) My 83 454 has a 410 rear axle, but the gear vendor improves the ratio and I use it all the time.

[cLaWz]

That is concerning on more then one level. One would think that with a smaller motor that the mileage would jump to some degree though I understand it will be proportionate to the total vehicle weight.

As for the 454 mileage, the avg I have seen is around 7-8 MPG which is a little higher than what we were getting before the head gasket went. From your statement it sounds like 10-13 is achievable but not sure on your setup. Current motor is stock with an unknown "upgraded" cam as the PO, my wifes stepfather, put it. Also has a Holley 600 CFM carb on it which I rebuilt and tuned per guides from forum members after I completed the rebuild. The C10 has a Quadrajet on it of unknown CFM which I guess I could look at. Hear they are the best your going to get for MPG but that statement could be wrong on so many levels. Haven't taken any gas mileage readings due to it not being street legal... having rear end brake issues that caused it to fail inspection.

[tucsonjwt]

Caution: Long post below:
Some more thoughts on gas mileage.
My 454 is a Goodwrench replacement (GM rebuild) motor which the previous owner had the dealer install (stock, I assume). My carburetor is a factory
Qjet which was professionally rebuilt. I added a manual choke (highly recommended) because the automatic choke (hot air or electric) never works properly. Without using the gear vendor I was getting 9 city/hwy unknown, but probably not good with a 410 rear axle. 7-8 mpg on a 454 is not normal - this indicates significant problems somewhere, or you are driving very aggressively - easy to do with a 454.
Regarding carburetors - I have had a few. Here is my experience:
73 454 - replaced with Carter Qjet replacement - ran well with 10-11 mpg
city. Problem: electric choke eventually did not work properly. Also,
choke valve was oversize, causing it to stick open and race the
engine periodically (a la Toyota). I filed off the edge of the choke
valve, but filed off too much, preventing full closure and hard start
when cold.
- next replacement carb was a Edlebrock (Carter like) carb. Never
choked properly - this is where I went with manual chokes. This
carbutetor, like the Carter, loaded up with varnish and died
because I did not drive it ofter enough. Replaced with another
Edlebrock - same experience.
76 350 - rebuilt Qjet from Autozone(?) - complete junk - struggled to get
9 mpg on the 350, choke stuck even with manual control.
83 454 - had the stock Qjet "professionally rebuilt" for about $325. So far,
so good, with the manual choke. There is a guy on the internet
in New York who says he uses only genuine GM parts for his
rebuilds - I would use him next time I need a rebuild.
One problem with all aftermarket carbs I had is that the air cleaner never lined up properly with the heat tube going down to the manifold. The Carter and Edelbrocks needed a spreadbore adapter for the 454 intake, so that also put the air cleaner up higher and required a cobbled up length of hose with radiator clamps (I needed the the hot air set up in place to pass emissions in AZ.)
General info: Old trucks need a lot of repairs - even if they have low miles. Things rust out, wear out, just go bad. Before I fix up an old truck again, I will ask myself the question: "Will it cost more to fix up this old truck or just get a newer/new one needing less/no repair?" The only reason I have an old truck is because I never wanted to get dirty/load up/abuse the new trucks I had - so why have a new truck? Looking back, I should have kept my 2000 Silverado V6 WT - would have saved enough in repairs over the past 10 years to pay for the truck - less frustration and time wasted dealing with less than competent mechanics.
As you probably know, it is still possible to get relatively rust free square bodies in the southwest for about $1500-$3000, where the previous owner already did some expensive repairs. If I went with an old truck again, I would look for a manual transmission, A/C, 350 or V6. If I were you I would check craigslist, then salvage your trucks for parts. Unless you need an open bed, nice Suburbans are available which are usually not as beat up as a pickup. In any case, without a V6 stick, expect no better than 10 mpg city/13 mpg. highway.
As a side note, (and under the category of none of my business) domestic tranquility is also a consideration. Since it looks like you live in a nice house in a nice neighborhood, my guess is the Mrs. doesn't care much for your truck collection An ugly truck(no offense meant) is probably acceptable if it is a reliable runner, so I would get to that point as quickly as possible.
Hope this isn't TMI/O (too much information/opinion).
Good luck

[hotrod_991]

I would but the C10 together but I am partial to half tons and manual trucks

[tucsonjwt]

OK, C10 it is. Re: SM465 - it has a long throw and the shifter is supposed to be loose (side to side). You can weld the shifter to the mounting but then the shifter will rattle all the time. Check the adjustment on the clutch. Mine tends to work loose from time to time, making it act like a bad clutch. The clutch fork should move quite a bit with the clutch depressed - mine was only moving about 3/4" - out of adjustment. An adjustment makes a lot of difference.

[cLaWz]

Originally Posted by tucsonjwt

OK, C10 it is. Re: SM465 - it has a long throw and the shifter is supposed to be loose (side to side). You can weld the shifter to the mounting but then the shifter will rattle all the time. Check the adjustment on the clutch. Mine tends to work loose from time to time, making it act like a bad clutch. The clutch fork should move quite a bit with the clutch depressed - mine was only moving about 3/4" - out of adjustment. An adjustment makes a lot of difference.

Ok so what changed it from the C20 with 454 to C10.. I'm curious now and really on the fence with this one. I can see the benefits and downfalls to each which is why I reached out for the wisdom on this board.

RE: The wife not liking the truck situation:

She actually wants the truck for herself when complete (So not happening!) so the collection isn't an issue. She is an impatient one though and does want it finished already whichever way we go. To add to that, she is the one that was scouring Craiglist for another truck with a good motor to try and build up as a 2nd one or a parts truck!

[red rumbler]

take the c 10 rip the interior optinons and drivetrain outa the red and black truck place them in the c 10 your good to go haha then again thats just my 2 cents lol

[tucsonjwt]

I thought you had decided on the C10, so I was agreeing with you.

As I stated, unless you drive about 15,000 miles per year with this truck, 454 vs. 350 will have the same gas mileage. A BIG however (as you noted) is that the C20 and 454 cost a lot more for parts, while C10 and 350 parts are much cheaper. I don't drive my C20 much (maybe 2K per year) so gas mileage is not a big factor. When I do drive it, I am often using the full payload capacity with my dump hoist conversion, or going to the dump. A C10 cannot safely handle big loads - it is more like a car (e.g. no floating rear axle, smaller wheels, etc.)
I think your wife is on the right track - you need another old truck (LOL)
Here is the bottom line: How do you plan to use your truck and how long do you expect to keep it? If you plan to keep it 3+ years, you will dump a lot of money in it, if you want a reliable vehicle. So: frequent driver, light load - C10 with V6 SM 465 or seldom driven, heavy load -C20 with fixed up 454.

My vote is still to find another square body that somebody already fixed up - they are out there. These trucks don't fetch much in the resale market because of the bad gas mileage. You can surplus these two trucks for parts and probably make $2K + on parts. Then buy another cherry late 70s to early 80s square body for $3-4K. There is a guy down in Whetstone AZ that has a lot of old trucks he rebuilds as a hobby. He recently had a cherry 77 C20 and a 76 GMC for like $3K each. I have seen near mint condition square bodies with low miles on ebay for like $4-5K. Unless you like the aggravation of rebuilding and cobbling together an old truck, I would get another one. Take it from somebody who already spent way to much money on these old trucks.