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Since I've broken the ice with the inane and obscure (5.7 Olds Diesel modification) it's time for a project that is a little more serious.
Some time back in 2010 I was daily driving a 2004 Malibu Maxx... nice car, especially for someone my height, but something I was growing bored with quickly as there was nothing I felt was worth doing to it. Browsing Craigslist I came across a rare bird.. a 1985 C10 with a mere 80,000 miles and an extended cab conversion for $4000. I had just finished purchasing my first house and took advantage of the first time home owners rebate that was available at the time. As I grew up around 73-87 trucks and cash to burn I couldn't say no.
Taking the truck for a test drive proved it was cherry. The truck was an original owner, having had the conversion done when it was brand spanking new and fitted with a stock style interior (many were coach built). During its life of hauling a salesman around, it eventually got a 350HO crate engine from GM Performance Parts to replaced the old and feeble 305 it came with. Behind the engine sat an all original TH350-C and a 10 bolt sporting 2.73 gears. It didn't launch hard, but with 330 hp on tap it could sure stretch out 1st gear; reaching 2nd somewhere north of 60 mph. Needless to say I was hooked and bought the truck off the fellow a few days later.
Aside from mild rust down in the cab corner, it really was a clean and unmolested truck; I quickly sold off the Malibu to promote this truck to daily status.
Rear interior space was limited. Due to the frame height, the floor was still the same height (and metal) as the bed. Few people could sit back here comfortably so it mostly serves as storage space.
Just a Vortec with a 600 CFM Holley, tappet cam and headers.
I did get rid of the badge, not to my taste.
For the better part of two years I drove the truck as-is, ultimately putting in a stronger secondary spring and smaller primary jets to get the carburetor dialed in. The previous owner had placed about an inch of fuel tubing over the throttle cable; I couldn't decide if that was to mask a poorly adjusted carburetor (from the crate, I might add) or because his high school grandson drove it for a while. On one hand I missed getting mid 20s for mileage and leather seats I had with the Malibu, but this truck had class.
But ultimately that boredom settled in again and I wanted something better than 13 mpg so I decided to fuel inject the engine. It was a Vortec after all, fitting it with a carb seemed like going backwards. So what better intake than the best intake never used in a pickup? The TPI!
After scoring a Scoggin Dickey lower manifold off eBay and a used 96 LT1 harness and PCM off Craigslist, I spent a winter piecing everything together. The long term plan was to use the LT1 PCM to control both the engine and a 4L60E which was to be swapped in at a later date when finances allowed. In typical Vortec fashion, I found the intake gaskets were less than desirable:
Otherwise the big challenges were finding a water neck that would fit here (Ultimately found a Chevy Astro neck worked):
And snacking an intake tube over the alternator to an air box from a 99 Silverado.
Having a LT1 PCM at least allowed it to be in the engine bay.
And all buttoned up. I was quite pleased with how this turned out.
I still want to plumb the air box into the fender cavity to keep it from drawing hot air.
The other big hitch was the distributor. I wasn't going to convert this thing to an Optispark setup so I went about wedging the guts into a TPI distributor. What you see here is the second iteration.
After machining and soldering a steel sleeve onto the shaft, I cut the center out of the Optispark to reused the wheel mount and bearing. This keeps backlash to a minimum and I found that originally trying to use the bushing resulted in a lot of wear and difficulty in keeping vertical backlash in check.
A hub was machined and shield added to it to shield the optispark from the flash of the arc and dust from contact erosion.
A weather pack connector was soldered on and the Optispark sensor housing notched to clear the cap (so future caps won't require modification).
A new rotor tip was made to allow for a larger timing advance window. Width was calculated based on the original Optispark tip; I think it came out to 0.75".
At the moment I modified a filter housing to serve as a surge tank; using the mechanical pump to lift fuel into it and an electric pump to draw fuel from it... it doesn't work well. Vapor lock is a big problem because the feed line is looped to the top of the housing; even though it draws from a stand pipe that dips down to the bottom of the filter. Vapor gets trapped in this loop and gives me fits in the summer. The pump is also incredibly noisy in that location. Ultimately I need to find a baffled TBI tank and convert it to work with a high pressure pump. The second tank will then get replumbed to serve as an auxiliary tank.
After literally hundreds of tunes, I finally got the truck into a reasonably well driving state. I drove it around for about a year until rebuilding a 4L60E and swapping it in. That vastly improved the driveability of the truck; but I still only get 13-16 mpg. Go figure.
Retrieving a $200 camper.
Coming up next: Tearing into the cab to repair cracking body filler and finding out what a hack job the conversion was.
Some time back in 2010 I was daily driving a 2004 Malibu Maxx... nice car, especially for someone my height, but something I was growing bored with quickly as there was nothing I felt was worth doing to it. Browsing Craigslist I came across a rare bird.. a 1985 C10 with a mere 80,000 miles and an extended cab conversion for $4000. I had just finished purchasing my first house and took advantage of the first time home owners rebate that was available at the time. As I grew up around 73-87 trucks and cash to burn I couldn't say no.
Taking the truck for a test drive proved it was cherry. The truck was an original owner, having had the conversion done when it was brand spanking new and fitted with a stock style interior (many were coach built). During its life of hauling a salesman around, it eventually got a 350HO crate engine from GM Performance Parts to replaced the old and feeble 305 it came with. Behind the engine sat an all original TH350-C and a 10 bolt sporting 2.73 gears. It didn't launch hard, but with 330 hp on tap it could sure stretch out 1st gear; reaching 2nd somewhere north of 60 mph. Needless to say I was hooked and bought the truck off the fellow a few days later.
Aside from mild rust down in the cab corner, it really was a clean and unmolested truck; I quickly sold off the Malibu to promote this truck to daily status.
Rear interior space was limited. Due to the frame height, the floor was still the same height (and metal) as the bed. Few people could sit back here comfortably so it mostly serves as storage space.
Just a Vortec with a 600 CFM Holley, tappet cam and headers.
I did get rid of the badge, not to my taste.
For the better part of two years I drove the truck as-is, ultimately putting in a stronger secondary spring and smaller primary jets to get the carburetor dialed in. The previous owner had placed about an inch of fuel tubing over the throttle cable; I couldn't decide if that was to mask a poorly adjusted carburetor (from the crate, I might add) or because his high school grandson drove it for a while. On one hand I missed getting mid 20s for mileage and leather seats I had with the Malibu, but this truck had class.
But ultimately that boredom settled in again and I wanted something better than 13 mpg so I decided to fuel inject the engine. It was a Vortec after all, fitting it with a carb seemed like going backwards. So what better intake than the best intake never used in a pickup? The TPI!
After scoring a Scoggin Dickey lower manifold off eBay and a used 96 LT1 harness and PCM off Craigslist, I spent a winter piecing everything together. The long term plan was to use the LT1 PCM to control both the engine and a 4L60E which was to be swapped in at a later date when finances allowed. In typical Vortec fashion, I found the intake gaskets were less than desirable:
Otherwise the big challenges were finding a water neck that would fit here (Ultimately found a Chevy Astro neck worked):
And snacking an intake tube over the alternator to an air box from a 99 Silverado.
Having a LT1 PCM at least allowed it to be in the engine bay.
And all buttoned up. I was quite pleased with how this turned out.
I still want to plumb the air box into the fender cavity to keep it from drawing hot air.
The other big hitch was the distributor. I wasn't going to convert this thing to an Optispark setup so I went about wedging the guts into a TPI distributor. What you see here is the second iteration.
After machining and soldering a steel sleeve onto the shaft, I cut the center out of the Optispark to reused the wheel mount and bearing. This keeps backlash to a minimum and I found that originally trying to use the bushing resulted in a lot of wear and difficulty in keeping vertical backlash in check.
A hub was machined and shield added to it to shield the optispark from the flash of the arc and dust from contact erosion.
A weather pack connector was soldered on and the Optispark sensor housing notched to clear the cap (so future caps won't require modification).
A new rotor tip was made to allow for a larger timing advance window. Width was calculated based on the original Optispark tip; I think it came out to 0.75".
At the moment I modified a filter housing to serve as a surge tank; using the mechanical pump to lift fuel into it and an electric pump to draw fuel from it... it doesn't work well. Vapor lock is a big problem because the feed line is looped to the top of the housing; even though it draws from a stand pipe that dips down to the bottom of the filter. Vapor gets trapped in this loop and gives me fits in the summer. The pump is also incredibly noisy in that location. Ultimately I need to find a baffled TBI tank and convert it to work with a high pressure pump. The second tank will then get replumbed to serve as an auxiliary tank.
After literally hundreds of tunes, I finally got the truck into a reasonably well driving state. I drove it around for about a year until rebuilding a 4L60E and swapping it in. That vastly improved the driveability of the truck; but I still only get 13-16 mpg. Go figure.
Retrieving a $200 camper.
Coming up next: Tearing into the cab to repair cracking body filler and finding out what a hack job the conversion was.
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