miSSed opportunity

[68 TT]

I bought a 1990 454 SS new and really liked it for a little while but it just wasn't very good at anything except spinning the tires. Having owned real muscle cars that truly performed at the same time it left me wishing Chevy had put a little more effort into the package. The things that were the worst about it were the anemic HP, average brakes, handling like an ocean liner, a ride height that made it look like a 4x4 and tires & wheels that belonged on a tractor just to get the list started.

I addressed all of those in spades in a ground up creation I built from scratch on a short bed regular cab 4x4 torsion bar chassis that eventually will get the front IFS reinstalled to make it selectable AWD or 2wd once I find a good Eaton E-locker for the 9.25" IFS and modify the headers to clear it. No point in having AWD if only one front tire spins or you don't have the power to do it.

I nicknamed this creation "miSSed opportunity" since I built it out of parts GM used on other trucks or SUV's of similar vintage that were close enough to the 1994 model year that they would have been at least in development at that time. I picked 1994 because 1993 was the last year for the real 454 SS truck.

The down side to this creation was that it still looks like a couple million other trucks on the road, just a whole lot lower, faster, better handling and stopping.

She is not finished yet but once I find the body pieces I need in good enough condition to use I will get the paint work done in classic 454 SS black and make it look the part. I will add 70 Chevelle style SS hood stripes to the cowl hood like are on there now but in the dark gray to match the 454 in the 454 SS bedside decals.

I never put together a build thread for it while I was building it initially but I still have plenty to do so there is lots left to document. I will post up what I have done so far as I have time.

Here is what it looks like right now. Just waiting for the engine & trans rebuild to be done (this winter hopefully) before I start in on the paint & body.

[68 TT]

Figured I should make a list of some of the major donor parts I used to build this truck.

Started with a 1989 C1500 RCLB truck that had a blown 305 TBI engine. All it ended up donating in the end was the completely gutted cab, T400 transmission, front seat, non-slider rear window and steel cowl hood along with the title. Everything else came from another source.

I put the 1989 cab onto a 1991 vintage K1500 torsion bar front suspension chassis that I stripped of all the parts and removed the front bump stops from the frame rails between the upper A-arms. Stripped, cleaned and painted. Polyurethane body bushings.

Rear springs are from a 1993 C1500 W/T with the helper spring removed to create clearance for the Cal-Trac bars to go on. Polyurethane rear spring eye and hanger bushings with greaseable Del-A-Lum front spring eye bushings for the Cal-Trac bars.

Rear axle is a 1993 vintage K2500 LD 6-lug 9.5" 14-bolt with 3.73 gears and a Gov-Bomb posi. It has held up so far to some pretty good abuse so it may just last. We will see. New Timken bearings and seals, Mobil 1 synthetic gear oil.

Front torsion bars are from the drivetrain and dash donor truck 1994 K2500 HD ECLB camper special 454 4L80E NP241 truck.

I tried a few different torsion bar keys to get the ride height I wanted but none gave me the drop I liked. Turned out that if I flipped the stock keys over and machined a new register in the arm for the bolt that they gave me the 4.5" drop I was looking for.

Front A-arms are from the 1994 K2500 drivetrain donor with polyurethane bushings. Ball joint angles were very bad with the 4.5" drop but I noticed the design of the upper A-arms was peculiar. I took the passenger side upper A-arm and put it on the driver side but upside down. It was magic, the ball joint angles were great. Added bonus was that it added a few degrees of caster too. Double bonus.

I installed the TBI 454 assembly and complete wire harness and PCM from the 1994 K2500 donor truck into the chassis but bolted it to the original 1989 C1500 trucks T400 transmission.

For the driveshaft it turned out that with just a new Strange slip yoke for 1350-series U-joints that the rear section of the 1994 K2500 two-piece driveshaft was the perfect length to work. Installed new Spicer solid body SPL 1350 U-joints in both ends and installed the new Strange transmission yoke then she was good to go.

Odd thing I found was that the driveshaft from the 1994 K2500 ECLB was 3.5" diameter but the one in my 1995 K3500 ELCB with dual rear wheels only had a 3" driveshaft.

Front brakes are the K1500 extended cab or HD brake option thicker rotors in the drilled & slotted variety. Rebuilt calipers, new flex lines, new Timken unit bearings, ball joints, tie rods, idler arm, pitman arm.

Rear brakes are dual piston caliper 2003 Suburban 13" with internal parking brake. Drilled & slotted rotors to match the front. New flex lines to the axle and from the axle to the frame. These required custom machined 80mm spacers to fill the gap between the older K2500 LD brake backing plate mounting flange and the Suburban caliper mounting bracket but this is where it pays to be a trained machinist with access to a machine shop after hours every now and then.

Eventually I will gather the parts to put the matching size front rotors onto it as well. The application is the 2003 to 2005 trucks with drum rear brakes. It will take a little monkey business to make them fit but I will figure it out.

Wheels are from a 2008 Silverado LTZ truck. Size is 20 x 8 or 8.5 can't remember right now. Sucks to get old. Tires are Cooper RS3-S summer only tread pattern tires in a size of 245/45-20. I even have a matching spare wheel & tire and center cap. I need to relocate the spare tire carrier hoist crossmember set before I can put the spare tire in though. As it is the rear roll pan causes the tire to be moved back toward the rear axle about 4".

Front sway bar is the largest one I could find on a 4x4 truck and it came from the 1994 K2500 drivetrain donor. Polyurethane frame mounts and end links.

Rear sway bar is from a 1999 Suburban. Polyurethane axle mounts and dog bone bushings. Had to make special axle tube mounts for it since the 9.5" 14-bolt I have has 3-3/8" diameter axle tubes.

I am missing about a years worth of photos so there are some big gaps in the process of this truck and my stepside so bear with me here.

[68 TT]

Exhaust system is started with a set of 2" tube Hooker Competition series headers designed for a 1968-72 Chevelle. They fit nearly perfectly with only minor clearance problems at the floor to firewall pinch weld seam on the passenger side. Easily bent out of the way.

Pipes are 2-1/2" tubing with mandrel bends and an H-pipe feeding into a pair of Flowmaster mufflers tucked together on the passenger side just before the rear axle.

No tailpipes for now until I get the spare tire carrier mount relocated and can install the spare tire so I have everything in place for proper fitment.

Even with the bone stock TBI 454 it sounds pretty good. Can't wait until it has a real muscle car idle after the engine rebuild.

[Stormin08]

nice start, neat approach...IT NEEDS THE FLARES ALL AROUND !

cant wait to see the end.

[68 TT]

Originally Posted by Stormin08

nice start, neat approach...IT NEEDS THE FLARES ALL AROUND !

cant wait to see the end.

Thanks. I agree. I have the flares and all the hardware & access hole plugs. I also have a template I made of the mounting holes from the bed of the 94 K2500 when I had the flares off of it when I painted it before using it to make my 95 K3500 DRW into a SRW. Just have to find the time to do the work.

[68 TT]

I totally gutted the 1989 cab down to the bare shell only leaving the rear window glass in place.

Cleaned every surface completely then lined it with sound deadener.

Installed a passenger side grab handle over the door that I snagged from a donor at the wrecking yard. Installed rivet nuts into the roof structure.

Installed a decent set of speakers into the rear B-pillars while I was back there since they are quite a pain to access later.

Installed an electrochromatic compass temp mirror out of a late 90's Suburban and ran the wires down the A-pillar. Installed the temp sensor on the hood latch support like on the Suburban and made all the connections. Works great. The auto-dimming feature is nice to have.

Since the 89 had some lame poor fitting aftermarket speaker headliner that I was always hitting my head on I decided to put a stock headliner into it. I cut down the extended cab headliner from the 94 K2500 and presto regular cab headliner in the correct oxblood red interior color.

[Palf70Step]

Really nice start on it. Looking forward to seeing it progress.

[68 TT]

I completely disassembled the 94 K2500 dash board and R-134a HVAC system. Scrubbed every inch of it inside and out with household cleaning wipes to remove all the years of built up yuck in and on all the duct work and parts. Wiped down after that with Windex to remove the tacky residue that the cleaning wipes leave. Squeaky clean and now the air coming out of the ducts doesn't smell like an old gym locker room.

Repainted all the dash parts with plastic & vinyl dye so everything matched and looked new again.

Reassembled the HVAC system with a new evaporator core, heater core and blower motor. Sealed all the joints in the system with non-hardening polyurethane sealant designed for high heat and UV exposure. Designed for roof and skylight repair but it works great for sealing up HVAC parts on vehicles. I have been using it for years and it works fantastic, plus it is less than $5 a tube for a caulking gun size canister. Makes for much better air flow coming out of the vents when you are not losing so much out of all the seams along the way.

Cleaned up the 94 K2500 tachometer gauge cluster, replaced all the bulbs, put the T400 gear indicator assembly in place and fit a new headlight switch to the bezel. Since I built this truck from scratch and everything mechanical is new or rebuilt (or will be soon) I didn't think it was right to leave the odometer on what it was from the parts truck that donated the engine core and dash so I reset the mileage. Nobody with half a brain could argue with that.

Goodbye 1989 no tach moon gauges dash and R-12 A/C system.

[68 TT]

Moving on to the front half of the HVAC system conversion to R-134a and to the 1994-up grille.

The core support is slightly different on the 1994-up vs the 1988-93 models so it had to be swapped out to use the 94 grille that I wanted to use. Slight differences in the way the bumper filler panel attaches too. I liked the looks of the inset ribs on the 94-up vs the 90-93 sport version where the whole surface is flush. Gives it more character.

Couldn't find a 94-up style grille specific red & black bowtie for sale when I needed one so I made my own. Looks OK but I will put a real one on there after paint. Found a few places that sell them now, just need to buy one.

Installed a new 1994 application R-134a accumulator, condenser, supply & return hoses and orifice tube. All new O-rings with PAG oil on them prior to install. Also installed a new big block auxiliary electric cooling fan and thermostatic switch. I figured out why these things are usually seized up when you find them at a wrecking yard. They spin in the wind even when the truck isn't running. Those poor bearings never get a break.

I made the mistake of putting a new aftermarket A/C compressor on there too. It seized up in just under a year with minimal use. I completely flushed the system parts and pulled a vacuum on it for an hour with my electric vacuum pump. Tested that it held a vacuum for a week before filling then filled the system with the GM specified amount of PAG 150 oil and refrigerant so there is no reason what so ever that pig should have failed. They had the balls to tell me that the warranty was void because I didn't pay a shop to flush my system out. Needless to say I bought the parts to rebuild and re-seal the original AC Delco compressor off the 94 K2500 that was leaking around the housing and spurred me on to replace it. Retard. Won't do that again. Now I have to pull the orifice tube out and trash it then flush the whole system and start over with a new accumulator because there is most likely debris from the POS compressor in the lines that will FOD out my freshened up AC Delco part if I don't.

Put a new set of black trim headlights and front turn signals on too. I liked the way they looked but in function the headlights suck. The light pattern they create is horrible compared to the other aftermarket headlights I have on my 98 Tahoe and even the stock headlights I had on my 95 K3500, hazy lenses and all. I will be swapping them out for a better set soon.

[68 TT]

Wanted to go with no side trim rubber strips on the body or bumpers so I bought a plain black front bumper and matching license plate bracket without the notches for the trim. I had a 1990 K1500 Z71 that had the 350 SS package and it came without the side trim stock. It looked so much cleaner than the 454 SS with the rubber trim on the side.

Also didn't like the look of the fog lights on the original 454 SS trucks so I chose to run a smooth front air dam. Installed that as well.

Two of the other things I didn't like about the original 454 SS trucks I addressed with the choice of the 89 truck cab I started with. The cab came without the cargo lamp and had a solid rear window. I hated the look of both of those things on the original but they were part of the 454 SS package and since I bought mine off a dealer showroom I got what I got. I don't think you could even special order one without them as I have never seen one that way.

[68 TT]

Since the 89 cab I started with had manual windows and door locks the factory didn't put the wire grommets in the door jambs. Had to install them so I could put the power window & door lock Silverado trim level doors from the 94 K2500 onto the 89 cab. Took the dimensions off the 94 cab so they would match up with the doors.

Hole is 1.75" in diameter and 1.75" in from body edge and 1.75" down from the body line in the picture. Center of hole for hole saw is 2.625" from body line and edge of body.

Sorry about the chicken scratch. Better than nothing.

Don't know why it is rotating the image. At least its not upside down.

[68 TT]

Added a Wilwood adjustable brake pressure valve into the rear brake line so I could dial in the balance front to rear with this hybrid system. Didn't take long to get it perfect to where the front and rear will lock up evenly. Made a big difference. Before the rear were overpowering the front. Sure sign I need to get on that front brake upgrade.

I don't think the rear ABS works at all so I think I am going to delete the parts and clean up the plumbing when I put on the Corvette 4-wheel disc master cylinder I have for it. It is currently running a 1.25" bore Hydro-Boost application master cylinder and a disc/drum prop valve and it works great but I know it will work better with the right parts on it. The master cylinder on there in the pictures was one of the stepped bore versions from a vacuum booster application and it wasn't performing the way I knew it should with the parts on it so I made the switch to the straight bore Hydro-Boost application version. Night and day difference. It will get even better with the Corvette master cylinder with the 4-wheel disc fluid volume.

I have a Wilwood GM style adjustable proportioning valve on my stepside and my Camaro. I think I will put one on here too to make it a trifecta.

Have to dial it back quite a bit when I put the winter tires on. These Cooper RS3-S tires grip like they have claws on dry pavement. Ice or snow it won't even get out of my driveway with them on. They weren't kidding when they say summer only tread pattern.

[hammered94]

Nice project!

[CANUCIT]

Looking Good

[mingoman]

Nice work!

[LT7A]

Very cool idea to take all the best parts for that application and combine them. I look forward to seeing the progress as you continue to put it together.

[SCOTI]

Originally Posted by LT7A

Very cool idea to take all the best parts for that application and combine them. I look forward to seeing the progress as you continue to put it together.

Agreed. Any updates?

[Ol Blue K20]

Originally Posted by scoti

agreed. Any updates?

x2!

[LT7A]

Checking back in on this one. Really like the concept.

[Shifty One]

In for this one as well!

[SCOTI]

Saw this image from Hot Rod's LS-fest West coverage & it reminded me of this build....

[Boog]

I'd never have thought I'd like a lowered truck with flares but I am really diggin the look.

[LT7A]

Well, Elvis was still in the building as of late July. Maybe he doesn't check his thread?