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August 2012 Chevy High Performance Q&A

Kevin McClelland Jun 27, 2012
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The Natives are Restless

I got several letters this month about one of my answers in the March issue. I have not gotten such pointed criticism since I once said that 307 small-blocks were not performance engines! I got letters for months about that because many people had built strong-running 307s and I must have been out of my mind. Well, if those folks would have gone back and read everything I said about 307s, they may have been a little more understanding of my comments.

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This brings me to my latest flirtation with disaster. First of all, I did make a mistake when I said, “There isn’t a TBI manifold on the market that offers the Vortec cylinder head bolt pattern.” Well, this error was quickly brought to my attention by Dr. Jamie Meyer and his staff at Chevrolet Performance, which, in fact, does offer a manifold under PN 12496821. This is a replacement high-performance dual-plane manifold that will bolt right up. This was an oversight on my part, and I’m glad you guys contacted us to get the message back out there about your manifold. Thanks.

Another letter writer felt I blew off the reader with a canned answer from one of our advertisers. This is the farthest from the truth. I recommend component parts packages from manufacturers all the time, but I do so because they have done all the engineering to make swaps and performance gains painless.

His main rub was that I didn’t answer the reader’s original question, which was how to install a 400 small-block under this 2 BBL throttle-body injection. He pointed out various ways the reader who wanted to increase his displacement could have done so with help from other aftermarket suppliers. This would have required the reader with the El Cam to have extensive tuning experience and purchase software to calibrate his TBI to work with the larger-displacement engine. I also hadn’t recommended a camshaft to work in this application with the throttle body. All valid points.

The bottom line is I feel it’s my responsibility with this column to help as many people as I can with my answers. If there are 5 percent of readers out there who could have done all the work and tuning on this package without a problem, that’s great. I have extensive experience trying to build high-performance TBI engines and tuning and have never been satisfied with the performance and driveability with high-performance TBI systems. They have inherent fuel-steer issues because of the throttle-body design that causes fuel distribution problems at various engine speeds. Also, when you try to make real power with a TBI, the injectors get too large and you have idle stability problems. This is not to say that TBI injection systems don’t work very well in stock applications.

I want to make sure what I write about is doable for most of my readers. If you readers out there feel you have the skill set to take it to the next level, please do. That’s how most of us have gotten there in the past.

Blown 408

I have an LQ9 that’s been prepped for 408 ci. It had 0.010 inch removed from the deck and bored to 4.030 inches with 4.0-inch stroke. I’ve had it assembled with Wiseco K464F3 pistons, and K1 Technologies connecting rods and forged steel crankshafts. The question I have is in regards to the heads. I have a Magnuson TVS 2300 out of a ’10 Camaro sitting on my bench waiting for a new home. I’ve a set of GM L92 ported #823 heads that I was thinking of using, but I’m unsure if these are the way to go. This is going in a lowered ’99 Z71 standard-cab Stepside with 285/50 R20 tires. Any information would be greatly appreciated.

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Jim Moran
Via email

First, we think your Magnuson blower has found a perfect new home. Yes, the L92 heads are a perfect top end to round out your 408 short-block. These, with the blower, will easily make some serious power. You didn’t mention what you have spec’d out for the camshaft, but any mild blower cam will bump the power easily into the 600-plus range.

The only potential issue we noticed from your letter is that you clipped the deck 0.010 inch. Did you check the deck clearance with the short-block assembled? We just finished building our LS2 with a complete Callies 4-inch rotating assembly and Diamond pistons. After line-honing the block, we needed to clip the deck to square up the head surfaces. The machine shop removed approximately 0.010 inch, and when we got the short together, the pistons were coming out of the deck by 0.018 inch with no rock. The factory MLS head gaskets are 0.051- to 0.053-inch thick. We almost went for it because of the aluminum block; we knew the deck was going to grow. Thinking about it for a bit, we decided to have Cometic build some 0.060-inch head gaskets to ensure the pistons wouldn’t get too friendly with the cylinder heads. Your engine is an iron block and the deck isn’t going to grow. We’d make sure what your deck clearance is with your surfaced block. Please don’t run it any tighter than 0.038 inch!

Did you say you had a sponsor for those 285/50R20 tires? That engine is going to shred them, and they are far from cheap! Have a blast.


Generation Serpentine

I have a ’69 Chevelle with a Mark IV 454 two-piece rear main seal. I have wanted to install a single serpentine belt system that would control power steering, alternator, and water pump, all in one. Being on a very tight budget, I cannot afford those very expensive aftermarket setup single serpentine belt systems. Even the GM single serpentine belt system PN 19172806 without A/C is out of reach. I am a firm believer of the wrecking yards, especially when they have their half-off sales. Could I use the serpentine belt system off a ’94 Chevy dualie 3500 with a 454 Gen V block on my Mark IV block? The water pump on the ’94 Chevy 3500 looks like it’s a long-neck, therefore I will be using the long-neck water pump on my two-piece rear main seal Mark IV. Could I use the power steering pump with hoses and the alternator on my ’69 Chevelle? I’m not sure if I could even use the alternator in my Chevelle. If not, what are my options, other than the pricey aftermarket setups?

Any help will be met with great appreciation. Keep up the good work.

Jose Rodriguez
Los Angeles, CA

Don’t you just love those half-off days at the self-service wrecking yards?

Yes, serpentine systems can be very pricey, and the GM alterative is much more affordable. If you’re scraping coins together to build your hot rod, the donor 454 Gen V front dress will do the trick. The GM kit is an assortment of production truck brackets and pulleys. Luckily, we strolled outside and checked out our ’93 3/4-ton Suburban with the Gen V 454 just like your donor. That drive system will bolt right onto the front of your early big-block. You must use the late-model water pump that matches the serpentine setup, as it is a reverse-rotation pump based on the belt routing. Your ’69 Chevelle has a standard-rotation, long-style water pump on it from the factory.

The power steering pump will work just fine feeding your ’69 power steering box. The only hassle there is that the ’94 pump uses O-ring–style power steering hoses and your ’69 uses flare-nut lines. You could take a fresh power steering line from the truck and have a hydraulic hose shop wedge the correct 3/8-inch flare-nut line end on the pressure hose. The return line will be a snap.

Finally, the alternator will also work and will be a major upgrade over the factory externally regulated alternator currently on your Chevelle. The original alternator could be a 36- to low 50-amp output alternator. The dualie alternator probably is at least 100-amp output from the factory, and could have a heavy-duty unit with an even higher output. All you need to do is to cut the connector off the ’94 wiring harness that connects to the alternator internal regulator. This connector should have one black small gauge wire coming from it to the truck’s warning lamp. On your Chevelle there is a brown-colored small gauge wire that comes from your dash warning lamp to the No. 4 terminal on your original voltage regulator. The voltage regulator is located next to the radiator tank on the driver side of the radiator core support. Disconnect this brown wire and extended it to connect to the one black wire coming out of the ’94 alternator. This will properly excite the internal regulator. You can disconnect the wires going to terminals two and three on the original regulator and insulate them. The No. 1 or F lug is commonly used as a junction block of the power lead from the battery on its way to the firewall plug, feeding everything under the dash.

Now that you have a high-powered alternator, you must upgrade the main load wire from your alternator to your battery. GM has run this load wire to various locations over the years from junction blocks, the main lug on the starter, or the battery. We prefer the last because then the regulator is able to see the load being placed on the battery and charge accordingly. When you run heavy-gauge wire down to the starter lug, it has the chance to be heated by the exhaust and close proximity to the block. As the wire’s temperature climbs, the resistance to electrical flow increases. If you run a single eight-gauge wire from the load lug on the alternator directly to the battery it will stay the coolest and give you the best charging path.

As we’ve said in the past, the OEMs have really built some good stuff over the years. We just need to figure out ways to incorporate them into our builds. Keep looking for money-saving options at the self-service yards. Good luck with your Chevelle.


Pump You Up

I am in the process of putting a 427 high-performance big-block in my ’69 Camaro (clone) and would like to know if there is any way to beef up the crossmembers to handle the extra horsepower or other modifications.

Dennis Forsberg
Minot, ND

We’re not completely sure what you need to beef up. The ’69 Camaro came standard with big-blocks from the factory. The front subframe will handle just about whatever you plan on throwing at it. Now, the factory rubber engine mounts are another story. They are great for reducing vibration into the driver compartment, but we’ve torn many apart over the years. These days, Energy Suspension has come to the rescue with polyurethane engine mounts that directly bolt in place of the factory engine mounts. You can pick up a set by ordering two of the PN 3.1118 mounts with chrome brackets (PN 3.1117 for gold zinc plated). While you’re at it, install the matching transmission mount, PN 3.1108.

Finally, if you’re looking to tighten up the complete car, Energy offers the HyperFlex system (PN 3.18118), which includes polyurethane bushings and mounts for your control arms, rear leaf springs, rear leaf-spring pads, front sway bar endlink sets, a unibody mount set, a trans mount, and ball joint and tie-rod end boots. This, in conjunction with the engine mounts, will help your Camaro take whatever you throw its way. It will make your early Gen I Camaro drive better than new.


’64 C10

My son wants to build a ’64 Chevy C10 that was his grandfather’s. My dad died a year ago, and this was the pickup my son always rode around in as a kid. That was when you could ride around in the bed of the truck. Now he wants to build it as a tribute to his grandfather. It is a longbed Fleetside. I was going to build an old-school small-block like the one I ran in a ’56 Chevy in the ’70 and ’80s. I had started to make my parts list when I came across a ’98 Camaro Z28 with an automatic that runs very strong. I could buy it for $1,500 less than I could build an engine ... so we bought it. Now, how many of the components off the Camaro can we use on the ’64? What I can’t use on the pickup I plan on using on my ’63 Chevy II station wagon, if possible. Also, would it be a good idea to use the wiring out of the Camaro, or have a wire harness custom-made for the pickup. We would appreciate any help we can get.

I would like to commend you and the magazine for such a great product. Your tech pieces are very well written and even someone without much experience can understand them. Thank you.

Ron & Chad Gardner
Via email

We’re very sorry to hear of your father’s death. Memories are sometimes all we have and building the C10 as a tribute is the best thing we can imagine. We restored a ’63 C10 Fleetside right out of high school. It was so bad and sucked up so much money that my mom called it the Yellow Rat Hole. Let’s get you and your son into your project, hold the pitfalls.

The engine and transmission out of the Camaro will be a great addition to the truck. It will have plenty of power to make it a real nice driver. The rearend is too narrow to fit under the truck; stick with the factory truck 12-bolt under the rear. The front suspension in the Camaro is a modified McPherson strut suspension. It uses a lower control arm, but the spindle attaches at the top to the shock that attaches to the shock tower. These round out the pickup points of the suspension. Again, you’ll want to stick with the unequal-length upper and lower control arms of the factory suspension. Please upgrade the springs, shocks, and especially the brakes—there are many disc brake kits on the market that will give you an added level of safety with the increased horsepower.

As for the wiring, you’ll need to use the factory computer and engine/transmission harness from the Camaro to control the powertrain. You didn’t say, but we’ll assume the Camaro is equipped with a 4L60E electronic-controlled transmission. This trans is completely controlled by the PCM. Check with Street and Performance for help with your wiring harness and swapping into your early iron. S&P can help with the factory harness or offer you a simple non-emission-legal computer and harness to support your engine and trans. They can help with just about any aspect of the swap.

You will need to upgrade the fuel system on your truck to support the EFI high-pressure fuel delivery. One of the challenges you’re going to run into is that the fuel tank is behind the driver seat in the cab. Keeping that thing sealed and vapor-free for the passengers can be tough. An aftermarket fuel tank may be a better option. Ecklers Classic Chevy Truck parts offer a really nice 19-gallon aluminum tank (PN 129317) that mounts between the framerails behind the rear axle. You have two options for fill locations, through the bed or putting a door and fuel fill through the fender. This tank is fully baffled. Another source we’ve used in the past is Rock Valley Tanks, which didn’t list a tank for your application, but we can’t believe the company doesn’t make one that will work. One of the beauties of the Rock Valley tanks is that you can order it complete with whichever intake pump you need to feed any engine.


Out to Pasture

I am sure you made a simple typing error in your answer to the Engine Dyno Information question in the Apr. ’12 issue when you stated, “The formula for horsepower is: Torque multiplied by 5,252 divided by engine speed equals horsepower.” That wouldn’t work. As you know the formula is torque times engine speed divided by 5,252 equals horsepower.

I enjoy your informative column. Keep up the great work.

Charles Villa
Via email

Boy, did I step in it this time! Thanks for bringing this to our attention. Formulas like displacement, swept volume, cc to cid, and horsepower are all up in the noggin. We can’t believe we screwed this one up! As one of our good friends, motorsports journalist Rick Voegelin, once said, “Doctors bury their mistakes, writers publish them.” Sorry for any confusion out there. CHP



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