"Stock" should mean "Stock"...Not heavily modified.....

"There's nothing stock about a stock car".  Robert Duvall's Harry Hogge uttered this immortal line to Rookie driver Cole Trickle ( Tom Cruise ) in the NASCAR classic "Days of Thunder". Truer word were never spoken. I had an argument with a guy the other day who was quoting the blistering 1/4 mile times laid down by participants in the Pure Stock Drags. Some of these cars were running a full 2 seconds faster than magazine road tests back in the day when the cars were new. "Of course those cars are going to go way faster" I said. "Their heavily modified." "Then how come they call it the "Pure Stock" drags?" he sneered. "Call it anything you want" "Those cars are far from "Pure Stock". I said. "Here's why". The rulebook is based heavily on the NHRA Stock and Super Stock class rules, which allow quite a bit of leeway. For example-one of the stronger Pontiacs that was running in the mid 11s is a picture-perfect sample of building a car to the LETTER of the rules. This was a 1970 RAIV Firebird. The RAIV had 10.75:1 compression, special round-port heads and exhaust manifolds,a hot cam and an aluminum intake and was grossly under-rated at 345 hp. ( 370 in the GTO-F-Bodies had a more restrictive exhaust system ) All that stuff only adds up to 15 hp over the base model? Right.  Anyhow-here's the list of definitely "non-stock" features on this car. Engines have to be within 15 inches of their original size. Since a 400 Pontiac is actually 401 cubic inches this car was 416. This was accomplished with a .030 overbore and using a crank with a 3.79 inch stroke instead of the stock 3.75. The builder also used 6.800 inch connecting rods and special pistons instead of the stock 6.675. ( NASCAR engine builders know longer rods give an engine more torque. This is why Nextel cup Small-Block Chevy engines run 6 inch rods when stock size is 5.7 ) The rulebook said that combustion chamber volume had to be at least 62cc. Stock RAIV heads have 72cc chambers. By milling the heads to get the 62cc chamber size this raises compression from 10.75:1 to over 12:1. Rules on camshafts say the cam has to be the original "type". In other words if a car came from the factory with a hydraulic cam then you have to run a hydraulic cam-you can't switch to a solid lifter cam. If the car came stock with a solid-lifter cam then you can run a solid-lifter cam, but you can't switch to a roller. However-there's no limitation on duration or lift. A stock RAIV has a cam with 308 / 320 advertised duration ( 231 / 240 @ .050 ) and .520 lift when used with 1.65:1 rockers. This Firebird was running a cam with 253 duration @ .050 and .632 lift with 1.65:1 rockers. The intake had to be a stock "type"-but the only limit on spacers was the hood coudln't be modified. So this guys NPD Repro RAIV / 455HO aluminum intake was port matched to the gasket and was running a two inch spacer. The carb had to be the original "Type" meaning a Q-jet-but this was a custom one that flowed 1000 cfm. The tranny was a TH400 with a 4,800 rpm converter and the guy was running 5.14:1 gears. ( You can run any axle ratio you want as long as the rear end is the stock "Type"-in this case an 8.5 inch 10 bolt ) Now you can see how this car with a stroker crank, longer connecting rods, 12:1 compression, a cam with .632 lift, a 4,800 rpm converter and 5.14:1 gears-could run mid 11s when a true stocker with 10.75 compression, stock bottom end, a cam with .520 lift, a 2,500 rpm converter and 3.90:1 gears could only run mid-13s!  This isn't an isolated example. The grand champion-an L88 Corvette that ran a blistering 11.43 and was almost disqualified-most tracks require anything quicker than 11.50 to have an 8-point roll cage and a driveshaft safety loop-had 13.5:1 compression-( up substantially from the stock 12:1 ) a cam with nearly .700 lift, a custom 850 Holley that flowed 1000 cfm, a 4,300 rpm converter and 4.88:1 gears. The fastest Ford was a '69 Mach 1 Mustang that had a 443 inch "FE" ( within 15 inches of 428 ) which was accomplished by boring out a 390 truck block,using a stroker crank, longer rods and custom pistons, a hot Lunati cam, a custom 735 Holley that flowed nearly 900 cfm, a C6 with a 3,800 rpm converter and 4.56:1 gears.  So these cars may have iron exhaust manifolds-but they are far from "Stock". Which is why their usually 2 full seconds quicker than any magazine road test you might read of your favorites. The cars wouldn't be nearly as fast but if you limited them to truly stock parts-i.e.-the exact duration and lift on the cams,stock compression ratios,stock drivtetrain parts-no musclecar I know of ever came from the factory with a 4,800 rpm converter and 5.14:1 gears-you'd have better racing and the times would be more indicative of what a truly "Pure Stock" car could achieve with an experienced driver. Anyhow before you start spewing about a "Stock" car make sure it's actually "Stock". Mastermind