Tips for building a Pure Stock champ....

Some of the buff magazines have coverage of the Pure Stock drags this month so I've gotten some inquirys from people wanting to know the best combination to run. There is no magic "winning" combination or formula. I can give you some advice on what to do to maximize your performance. If you already have a car your planning to run-then you have to tailor your modifications to that car's strengths and weaknesses. If your going to buy a car to run, you need to think carefully. For example if you want a big-block Chevelle what year should you run? From 1966-69 the largest engine was a 396. From 1970-72 you could get a 454. Ditto for a Pontiac GTO. Fom 1964-66 they had 389s. From 1967 on the 400 was standard equipment and the 455 became optional in 1970. So should run a '70 and later model to take advantage of the monster 454 Chevy and 455 Pontiac right? Maybe not. a 1964 GTO with a Tri-Power 389 is rated at 348 hp. Let's say it has a 4-speed and a 3.90:1 rear end. And a '64 GTO weighs about 3,400 lbs. A '70 GTO with a 455 is rated at 360 hp. And it weighs 4,070 lbs. Let's say it's an automatic with 3.23:1 gears. Or a 4-speed with 3.55:1s. ( 455 GTO's didn't have stiff gearing options in 1970; although rated at 360 hp; it was a "station wagon" engine. The vaunted 455HO which had RAIV heads and intake and exhaust coupled with the "068" cam didn't debut until 1971. The RAIII and RAIV 400s were considered the top performance options in 1970 and could be had with 3.90:1 or 4.33:1 gears ). Guess what? 12 hp won't overcome a nearly 700 lb weight advantage and the mechanical advantage of stiffer gearing. All other things being equal-the '64 GTO wins the drag race easily even though it's the car with "less" power. Ditto for the Chevelle owner-early Chevelles are much lighter than later ones; and the under-rated L78 375 hp 396 ( The L78 was intially rated at 425 hp in the 1965 Corvette. Later models in the Chevelle line were-down-rated for insurance purposes, but the engine was the same. )  had everything-heads, cam carb and intake that the mighty 450 hps LS6 454 had. Now if your a Ford Guy the shoe is on the other foot. A '72 Mustang has a 351C as the largest engine. A 1969 or 1970 model can use a 428.  We could go on for days with various examples but you get the idea. Anyhow here's some good tips that work, regardless of make or model. # 1. Always build the lightest car that you can. It's simple power-to-weight ratio. All other things being equal-a 3,000 lb car with a 300 hp engine will run just as fast as a 4,000 lb car with a 400 hp engine. However-a 300 hp engine is a lot easier and cheaper to build than a 400 hp one.  So build a Nova instead of a Chevelle. A Duster or Dart instead of a Charger or Road Runner. A Maverick instead of a Torino.  # 2. Always build the biggest engine you can afford. For example a 350 Chevy makes way more power and torque than a 305, yet costs no more to buy or build. In fact-since I have seen stroker rotating assemblys that have the crank, rods, pistons, rings and bearings and an oil pump as low as $399-it really doesn't cost any more to build a 383!  On the other hand if you have a good 400 Pontiac or 383 Chrysler or 396 / 402 Chevy-don't throw it away and then spend a mint buying and building a junk 440, or 454 or 455.  The key word is "afford." # 3. Don't forget mechanical advantage. The strongest engine in the world will be a dog if it's saddled with 2.56:1 gears. Run the gear that will give you the best 1/4 mile time. On a solid-lifter, high-winding 302 '69 Z/28-4.56:1s would rock. On a hydraulic cammed 350 hp 396 Chevelle-some 3.73:1s would be better-4.56:1s would cause it to run out of rpm before the end of the 1/4!!  # 4. Traction. All the power in the world doesn't do you any good if you can't put it to the ground. Excessive wheelspin loses more races than any other factor. Check your class rules; some allow traction bars or pinion snubbers, some don't. You can also play with tire size and tire pressure. Most classes allow sticky street tires like Mickey Thompson or M&H, some allow drag radials, some don't. Maybe next time we;ll talk  about a specificic car and how to really fine-tune everything. Mastermind