Bonus Test!
We had this hideous homebuilt intake manifold sitting on the shelf for about three years and figured there would be no better opportunity to test it. The story here is that a while back, we figured a higher-revving LT1 engine would enjoy the benefits of a larger intake plenum. So we headed down to the metal store and picked up a bunch of aluminum and started hacking away at a stock LT1 intake. We removed the entire top of the intake and welded a 2-inch tall extension to the length of the plenum. This precluded the use of the factory fuel crossover so some minor modifications were made to that as well. Some port matching was also in order to meet the runners of the Edelbrock heads.

As soon as we were done wringing the most we could out of the Edelbrock intake, we left the big cam in there and installed what we lovingly call the "bread box" intake. We honestly had no idea how it would fare compared to the beautiful red intake that had performed so well. Not surprisingly, the gurus from the big E knew their stuff as their LT4 intake bested the bread box through almost the entire rpm range ... until 5,900 rpm that is. From there on up, the bread box did as it was designed to do and was able to feed just a little more air to the mill and pick up just a couple of horses. Was it worth it? Maybe, if you plan on using only a high stall converter and revving the wee out of the engine. Otherwise, save a bunch of time and effort and stick with what papa Vic puts out.

Edelbrock Top-End Kit
Under a mass of wires that resembles the lower intestines of someone who overdosed on Skittles lies a wolf in wolf's clothing. The heads, intake, and throttle body of the Edelbrock LT4 kit are beautifully crafted pieces that scream power and deliver at a competitive price. We wanted to do this test with a combination that was in fact reasonably priced and readily accessible to the average rodder. There are a number of custom head porters out there who could no doubt out-perform the LT4 Xtreme heads, but at what cost? The Edelbrock heads showed up to our door in ready-to-run condition. The decks were perfectly level with no need for extra surfacing as some aftermarket heads require. Screw-in studs and guideplates precluded the need for expensive narrow body self-aligning rocker arms. In fact, we were able to use standard issue COMP rocker arms under the OEM valve covers by merely cutting out the tin tie-bar in the valve cover and installing a piece of tubing to make up the difference.

The heads use lightweight 8mm valve stems with 2.02/1.57-inch stainless steel valves and beehive springs that according to our spring tester were easily good for more than .600 lift. They have fully CNC-ported combustion chambers as well as CNC-blended intake and exhaust runners. The only issue we had was that the large 195cc runners had a port entry that was larger than either the LT1 or LT4 intake gaskets. This was easily remedied by using a set of Felpro 1206 gaskets, and punching out a new set of boltholes in them. With flow numbers better than the factory LT4 heads and much less scarce, it makes the Edelbrock heads an easy choice.

The Edelbrock LT4 intake manifold is every bit as nice as the heads. It uses an Air-Gap design to cool the runners and plenum and accepts all the factory sensors and bolt-ons as well as a 58mm throttle body without any extra grinding. A super nice red powdercoat mimics the finish of the GM LT4 intake. No port matching was required to mate the Edelbrock intake to their heads. Though they suggest some matching may be required if using this intake on factory heads. Together, the pieces of the Edelbrock top-end kit form a perfectly matched combo clearly capable of massive power.

EMS-Pro
Controlling a fuel-injected engine can be very complex, or very simple. The options for an LT engine vary from using the stock computer and reflashing it with one of the available programmers, to running a complete stand-alone fuel management system. We've been down the road of reprogramming the stock ECU, and though it does work well, we wanted something that was easy to deal with outside the chassis of the car and didn't take forever to download each change. That left us trying to decide what fuel management system to use. There are tons of them out there, and honestly, they are all pretty darned good. We didn't want something that, in reality, could cost more than the car we yanked the engine from. Having used the home-brewed Megasquirt before on a few projects, we decided on the EMS-Pro from EFI-Source that uses the latest Megasquirt technology and Megatune software. With a flying-lead harness, a set of injector clips, an air intake sensor, coolant temp sensor, and narrow-band O2 sensor (all just plain-Jane GM stuff) our whole system cost less than half of some of the more popular systems. We just added a throttle position sensor, fuel rails, and injectors from a stock LT1 and we were in business.

There are a number of options for triggering the ECU. After lengthy searching, we found a way to run it based off the Optispark pickup, but we wanted something a little simpler. Following the do-it-yourselfer attitude of the Megasquirt world, we rounded up an old Holley hall-effect crank trigger wheel, scavenged a crank sensor from an LS1 engine, and cobbled up a sensor mount. Correctly assuming there would be a learning curve, we got everything together on our run-in stand instead of wasting precious dyno time. The initial setup was fairly straightforward, and the engine fired up without much effort. The problem came whenever we tried to rev it above 3,000 rpm and it would stutter and stumble. After lengthy calls to EFI-Source tech dude Scott Clark-aka "Dieselgeek" on the boards-we went through a couple of different crank triggers and sensors, but it turns out we were just getting noise in the crank trigger wires from having them routed too close to the injectors. A quick rerouting and the engine ran like a dream. Tuning changes were quick and easy, and most didn't require turning off the engine, though I wouldn't suggest that technique in a moving car. For just over a grand, we had a fully optioned ECU with 12x12 resolution tuning tables that worked as good as anything on the market.

MSD For LT1
In their quest for ignition perfection, MSD is constantly innovating and updating. Case in point: the billet LT1 Optispark distributor. They've taken the OEM design to the next level with this masterpiece. A billet aluminum base featuring large ball bearings for stability and an extra hold down bolt to reduce leakage are standard fare. What really sets it apart is the adjustable dial that allows the tuner to advance or retard the spark timing +/- 5 degrees at the twist of a screw. They've also included an upgraded optical pickup that is significantly improved over stock. Add those tricks to their top-shelf cap and rotor and it should be the last Opti you'll ever have to buy.

The distributor isn't the only place where MSD is moving forward. Recently, they unveiled their 6AL-2 ignition box. Destined to take the place of the venerable 6AL that has been a staple in racing and hot rods for years, the 6AL-2 uses digital technology instead of an analog design. This allowed MSD to put additional features like a built-in two-step and optional hall-effect trigger pickup into a smaller case. More features, less space, what's not to like? As always, they even went through the effort of printing their wiring diagram on the back of the box for those of us who immediately destroy all instructions upon receipt.

WHERE THE MONEY WENT
Item: Part No: Price:
Used LT1 complete engine core NA $150
Eagle cast steel 3.75-inch stroke crank 10352375057I $259.95
Eagle SIR 5.850 rods SIR5850BBLW $264.95
Wiseco flat-top pistons K166AS $653.99
Total Seal gapless second piston rings NA $259.39
Mahle/Clevite rod bearings CB663P $22
Mahle/Clevite main bearings MS909P $25.95
Mahle/Clevite cam bearings SH290S $17.95
Felpro conversion gasket set QCS9966 $69.95
Felpro head gaskets 1074 $75.90
Felpro intake gaskets 1206 $16.95
Felpro valve cover gaskets QVS50088R $16.25
COMP Cams Type R Magnum lifters 875-16 $207.88
COMP Cams Magnum pushrods 7608-16 $99.95
COMP Cams Gold 1.5 roller rockers 1004-16 $299.95
Cloyes LT1 timing set C3039 $87.95
Melling std. volume oil pump M55 $19.95
Enginetech oil screen S55S1 $7.95
Edelbrock LT4 Extreme heads 61939 $2,059
Edelbrock LT4 Air-Gap intake manifold 7109 $509.95
Edelbrock 58mm throttle body 3810 $315.95
Edelbrock LT1 camshaft 2108 $285.95
PARTS SUBTOTAL:   $5,727.71

LABOR
Bake and shot-blast block $40
Torque plate hone block $122
Deck block $110
Clean, install cam bearings and freeze plugs $75
Balance rotating assembly $225
File fit rings $50
Assemble engine $375
LABOR SUBTOTAL: $997

EFI PARTS
EFI-Source EMS-Pro ECU $795
EFI-Source flying-lead wiring harness $95
EFI-Source fuel injector pigtails (8) $96
EFI-Source narrow band O2 Sensor kit $20
EFI-Source coolant and air temp sensor kit $35
Crank trigger wheel – used $20
Hall-effect pickup from LS1 – used $5
EFI SUBTOTAL: $1,066

IGNITION PARTS
Item: Part No.: Price:
MSD Billet Optispark distributor 83811 $499.95
MSD spark plug wires 32149 $109.95
MSD 6AL2 6421 $251.95
MSD Blaster SS coil 8207 $40.95
NGK spark plugs TR55 $21.52
Ignition subtotal:   $924.32
BASIC ENGINE TOTAL:   $8,715.03

CAMSHAFT TESTING
Item: Part No.: Price:
remove Edelbrock cam 2108 -$285.95
COMP Cams LT1 cam option 07-503-8 $249.95
COMP Cams LT1 cam option 07-467-8 $249.95
COMP Cams LT1 cam option 07-468-8 $249.95
Deki 60 lb/hr injectors NA $450
TOTAL COST:   $9,129.03

On The Dyno • LT Cam Test Results
RPM TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
  TQ HP TQ HP TQ HP TQ HP TQ HP
3,600 447 306 436 299 443 304 393 269 383 263
3,700 448 316 444 313 446 314 397 27 394 279
3,800 454 328 459 332 453 328 399 289 410 296
3,900 459 341 462 343 459 341 404 300 415 308
4,000 461 351 463 353 466 355 426 324 419 319
4,100 459 359 464 362 474 370 441 344 436 341
4,200 464 371 468 375 474 379 445 356 442 353
4,300 463 379 468 383 480 393 453 371 447 366
4,400 460 386 467 391 483 405 456 382 450 377
4,500 459 393 463 397 479 410 453 388 449 385
4,600 453 397 459 402 477 418 448 393 456 399
4,700 450 403 453 405 473 423 450 403 450 403
4,800 449 410 446 407 470 430 450 411 450 411
4,900 448 418 454 423 469 437 451 421 448 418
5,000 439 418 448 427 465 443 451 430 446 424

5,100 433 421 447 434 462 449 453 440 456 443
5,200 428 424 438 434 457 452 459 454 447 443
5,300 419 422 434 438 453 457 454 458 452 456
5,400 416 428 429 441 447 459 453 466 450 463
5,500 413 432 421 440 443 464 452 474 443 464
5,600 399 425 416 444 433 461 444 473 442 472
5,700 395 429 411 446 429 466 448 486 442 480
5,800 388 428 403 445 423 468 440 486 439 485
5,900 383 430 402 451 419 471 436 490 440 494
6,000 375 428 394 450 410 468 429 491 433 495
6,100 365 424 385 447 400 465 427 496 427 496
6,200 354 418 375 443 394 465 420 496 422 498
6,300   416 499 418 502
6,400 411 500 411 501
6,500 402 498 406 502
6,600 393 494 402 505

TEST 1: Edelbrock top-end kit w/Edelbrock 2108 cam 218/218 @ .050 .525/.525 lift 112 LSA
TEST 2: Edelbrock top end w/COMP 07-503-8 cam 224/230 @ .050 .503/.510 lift 112 LSA
TEST 3: Edelbrock top end w/COMP 07-467-8 cam 230/236 @ .050 .542/.537 lift 113 LSA
TEST 4: Edelbrock top end w/COMP 07-468-8 cam 242/248 @ .050 .549/.545 lift 113 LSA
TEST 5: "Bread box" intake w/COMP 07-468-8 cam 242/248 @ .050 .549/.545 lift 113 LSA

SOURCE
MSD IGNITIONS
El Paso
915-857-5200
www.msdignition.com
Comp Cams
3406 Democrat Road
Memphis
TN  38118
800-999-0853
http://www.compcams.com
Edelbrock (Carbs)
800-416-8628
http://www.edelbrock.com
Revolutionary Performance And Machine
12049 B Lebanon Rd.
Mount Juliet
TN  37122
615-754-5512
www.revolutionaryperformance.com
EFI Source
320 South Franklin Street
Boyertown
PA  19512
610-473-2089
www.efisource.com