IHRA STK/SS Horsepower Adjustments

9/5/11

•          350 / 345/360 reduced 5 to 355 HP
•          350 / 345/365 reduced 5 to 360 HP
•          350 / 355/375 reduced 10 to 365 HP

8/17/11

•          460 486 reduced 15 to 471 HP
•          460 535 reduced 15 to 520 HP

6/7/11

•          2010 Ford 281/ 235/235 increased 5 to 240 HP.
•          1971 Buick 455/ 315/330 increased 2 to 332 HP.

5/10/11

•          1999-2002 GM Camaro, Firebird and Trans Am. 346 - 342 + 7 to 349 HP.

5/3/11

•          350 / 300-300 increased to 305 HP.

3/3/11

Stock  Eliminator HP adjustments:

•          2002 Pontiac 346/325/342 increased 5 to 347 HP.
•          2009 Dodge 360/275/284 increased 20 to 304 HP.
•          2010 Dodge 345 305/326 increased 15 to 341 HP

2/1/11

Stock  Eliminator HP adjustments:

•          350 /300-305 decreased to 300 HP.
•          350 /330-340 decreased to 330 HP.
•          350 /385-395 decreased to 390 HP.

•          302/320-300 (Y302 head 285 HP) (X303 head 295 HP)
•          392/430 (X head 390 HP) (Z head 410 HP)

2/9/10

Stock  Eliminator HP adjustments:

•          1972 Oldsmobile 350/250 increased 7 to 257 HP

12/23/09

Super Stock  Eliminator HP adjustments:

•          Ford 460/220/300 increased 5 to 305

9/22/09

Stock  Eliminator HP adjustments:

•          1969 Chevrolet Camaro 396/375/390 increased 5 to 395 HP.
•          1982 Jeep 242/190/170 increased 5 to 175 HP.
•          1985 Chevrolet Camaro 305/175-253 increased 5 to 258 HP.
•          1991 Chevrolet Camaro 350/245-260 increased 5 to 265 HP.

7/28/09

Stock  Eliminator HP adjustments:

•          1986 Ford and Mercury 302/205 reduced to 200 HP.

3/29/09

Stock  Eliminator HP adjustments:

•          1985 Chevrolet Camaro 350/150-250+5 to 255 HP

1/10/09

Stock Eliminator HP adjustments:

• 1973 Ford and Mercury 351-246/253/294+10 to 304 HP (GT only)

5/7/08

•          1996 262 Chevy 170 HP + 10  to 180.

3/1/08

Stock  Eliminator HP adjustments:

•          1969 Chevrolet Corvette 427-430(L-88) was 435-5 to 430 HP (cam lift 560/580)
•          1964 Chrysler (Max Wedge) 426 415 HP -5 to 410 HP

1/20/08

Stock  Eliminator HP adjustments:

•          Ford 392 (X head) /430 410 reduced to 405
•          Ford 392 (Z head) /430 reduced to 425
•          Ford 347 450 hp rated at 430

11/5/07

Stock  Eliminator HP adjustments:

•          1994 Chevy 265 / 200 HP + 15 to 215 HP
•          1966 Chevy 165/100 HP -5 to 95 HP
•          1963 Chrysler (Max Wedge) 426 415 HP -10 to 405 HP       

10/12/07

• 1967 Ford Shelby 428 345/366 + 4 HP to 370 HP (Auto)

6/1/07

• 2003 Dodge Neon 146-215 HP + 4 to 219 HP

4/30/07

All vehicles classified as stick only or auto only, accepted to use automatic when listed as stick only, and accepted to use stick when listed as automatic only.

Stock  Eliminator HP adjustments:

• 1969 427 Chevy Camaro 425/425 + 3 to 428 HP
• 1985 305 Chevy Malibu Wagon 175/245 + 3 to 248 HP
• 1967 Ford Shelby 428 350358 + 3 to 361 HP   (Stick)    
• 1967 Ford Shelby 428 345/363 + 3 HP to 366 HP   (Auto) 
• All  Ford 1969 428-335 (375 -10 to 365hp) in any non ram air applications
• All GM1968 thru 1970 230-140 (140-5 to 135hp)
• All GM1968 thru 1974 250-155,145,110,100 (140hp)

Pure Stock

• All GM Camaro and Firebird 1994-1997 LT-1 315 hp

11/29/06

Stock Eliminator horsepower adjustments:

• 1967 Ford Shelby 428/ small valve/aluminum head/automatic was 358 + 5 to363 HP
• 1967 Ford Shelby 428/small valve/aluminum head/standard was 355 +3 to 358 HP
• All Chevrolet Crate 350/355/365 + 10 to 375 HP 1973
• Ford and Mercury 351-246/253/291+3 to 294HP
• 1990 Chevrolet Corvette 350-247/250 was 260+5 to 265HP
• 1969 Chevrolet Corvette 427-430(L-88) was 440-5 to 435HP(cam lift 560/580)
• 1969 Chevrolet Camaro 427-430(ZL-1) was 440-10 to 430HP
• All Ford Crate 302/285/265-10 to 255HP

Super Stock Eliminator horsepower adjustments:

1971 Ford Mustang 429-375/380-30 to 350HP

4/28/06

Stock Eliminator horsepower adjustments:

• 1973 Ford and Mercury 351-246/253/285+6 to 291 in all Stock GT applications
• All Ford 302/320/300 Aluminum Head Crate Engine / Y 302 Al Head-10 to 290 HP
• All Ford 302/320 Aluminum Head Crate Engine/ X 303 Al Head -20 to 300 HP
• All 1966 Chevrolet 283/220/210 + 5 to 215 HP in Full Size Wagons

12/23/05

Pure Stock horsepower adjustments:

• 1979 Chevrolet 305-160/235/245 – 15 to 230 HP
• 1968 Pontiac Firebird Ram 1 400/335/340/355/360 +5 to 365 HP

Stock Eliminator horsepower adjustments:

• 1969 Mercury Cougar 428-335/375 non ram air -5 to 365 HP
• 1969 Pontiac 350-325 and 330, -10 and -15 to 315 HP
• 1971 Chrysler, Dodge, Plymouth 318-230/195 -10 to 185 HP
• 1972 Chrysler, Dodge, Plymouth 318-150/195 -10 to 185 HP
• All Mopar 360/360 Crate Engines -15 to 345 HP
• All Mopar 360/380/370 Cast Iron Head Crate Engines -15 to 355 HP
• All Mopar 360/380/380 Aluminum Head Crate Engines -15 to 365 HP
• All Chevrolet 454/425 Cast Iron Head Crate Engine / Accepted Aluminum Head
12363392 +15 HP to 440HP
• All Ford 302/320/300 Aluminum Head Crate Engine / Accepted Aluminum Head
X 303 + 20HP to 320HP

9/29/05

• 1968 Pontiac Firebird Ram Air 1 400/335/340/355 to +5 to 360 HP

8/31/05
Pure Stock horsepower adjustments:

• 1972 Plymouth Barracuda 340/240/285 +5 to 290 HP

TOP STOCK: (effective 8/4/05)

• 514 Ford CM @ 430 HP - 5 HP to 410 HP
• 360 / 340 CM Mopar - 5 HP to 335 HP (aluminum head version only)
• 360 / 345 CM Mopar -5 to 340 HP
• Fastburn 350/340/355 - 5 HP to 350 HP
• GM LS-1 (alum) 355 HP - 10 HP to 345 HP

• 1966-1970 CHEV 396/375/370 HP + 15 hp to 385 HP
• 502/502 / 435 HP + 5 hp to 443 HP
• 500 / 445 Mopar (Wedge) CM + 5 HP to 443 HP

6/1/05 (effective 6/6/05)

Pure Stock horsepower adjustments:

• 1972 Buick GS 455/250/345 +10 to 355 HP
• 1968 Pontiac Firebird Ram Air 1 400/335/340 +15 to 355 HP
  
  Stock Eliminator horsepower adjustments:
• 1987 Pontiac Formula 305/185/238 +3 to 241 HP
• 1986 Chevrolet Camaro 305/165 / 253 and 305/190 / 253 + 10 to 263 HP

Super Stock horsepower adjustment:

• 1986 Ford and Mercury 302/200/240 -20 to 220 HP
  

2/4/05

1964-66 Chevy 283 / 220 HP increased to 215 (automatic combos only)

1/12/05

TOP STOCK HP ADJUSTMENTS (effective 1/12/05 )

1966-1969 CHEV 427/ 425 / 400 HP - 5 HP to 395 HP

514 Ford CM @ 430 HP - 5 HP to 415 HP

500 / 445 Mopar (Wedge) CM - 7 HP to 438

360 / 345 CM Mopar - 5 HP to 340 HP (aluminum head version only)

360 / 350 CM Mopar -5 to 345 HP

6/2/04

1965 Ford 289 / 271 reduced to 245 hp (pure stock only)

12/19/03

1994 Camaro LT-1 350 275 / 325 reduced to 315 hp (pure stock only)

8/13/03

TOP STOCK HP ADJUSTMENTS (effective 8/13/03)

Fastburn 350/340/365 - 10 HP to 355 HP

1966-1970 CHEV 396/375/385 HP - 15 hp to 370 HP

GM LS-1 (alum) 365 HP - 10 HP to 355 HP

Camaro / Firebird LT-4 350 / 345 - 10 HP to 335 HP

1970 Stage 2 Buick - 5 HP to 385 HP

1966-1969 CHEV 427/ 425 / 405 HP - 5 HP to 405 HP

427/470/ 430 (ZL-1) - 15 to 415 HP

514 Ford CM @ 430 HP - 10 HP to 420 HP

428/335/385 CJ (F5 Head) - 10 hp to 375 HP

500 / 430 Mopar (Wedge) CM + 15 HP to 445 HP

472/525/415 crate hemi - 5 HP to 410 HP

440/six pack - 10 hp to 375 HP

67-71 426 / 410 Street Hemi - 5 HP to 405 HP

360 / 350 CM Mopar - 5 HP to 345 HP (aluminum head version only)

1963-64 Mopar 426/425/415 hp HI Comp. Max Wedge -5 to 410 HP

6/11/03

TOP STOCK and Pure Stock HP ADJUSTMENTS

360/340 CM Mopar +10 to 350 HP (top stock only)

502/502 / 435HP +3HP to 438HP (top stock only)

67-71 426/415HP Street Hemi -5HP to 410HP(top stock only)

1987- 89 Ford 302 / 225 / 215 + 8 HP to 223 (stick combos only)

5/13/03

PURE STOCK HP ADJUSTMENTS

1972 Buick GS 455/250/330 +15HP to 345

1964-66 Chevy 283/220/210 +5HP to 215 (automatic combos only)

1987-89 Ford 302/225/210 +5HP to 215 (stick combos only)

1/13/03

STOCK HP ADJUSTMENTS (effective 1/14/03)

·1964-66 283 / 220 HP reduced to 210 (automatic combos only)

1/6/03

TOP STOCK HP ADJUSTMENTS (effective 1/6/03)

· Fastburn 350/340/355 +10hp to 365 HP
· 514 Ford CM @ 430 HP
· 500 Mopar (Wedge) CM @ 430 HP
· 360/335 CM Mopar +5 to 340 HP 
· 351/335 CM Ford + 5 to 340 HP

8/28/02

TOP STOCK HP ADJUSTMENTS (effective 8/29/02)

Fastburn 350/340/365 -10hp to 355 HP

1966-1970 CHEV 396/375/390 HP -5 hp to 385 HP

1966-1969 CHEV 427/425/410 HP -5 hp to 400 HP

428/335/390 CJ (F5 Head) -5 hp to 385 HP

7/31/02

Super Stock

1965 Chevrolet 327 / 250 / 260 HP reduced to 255

Stock

1965 Chevrolet 283 / 220 HP reduced to 210 (automatic combos only)

6/19/02

TOP STOCK HP ADJUSTMENTS (effective 6/24/02)

Fastburn 350/340/360 + 5hp to 365 HP

GM LS-1(alum) 355 HP +10 hp to 365 HP

502/502/423 HP +12 hp to 435 HP

428/335/385 CJ (F5 Head) +5 hp to 390 HP

5/28/02

STOCK HP ADJUSTMENTS (Crate Motors - effective 5/28/02)

350/345/355 @ 360 HP (dish version)

350/345/355 @ 365 HP (flat top version)

350/355/365 HP

360 / 300 / 315 hp (Commando) increased to 320 hp.

5/23/02

TOP STOCK HP ADJUSTMENTS (effective 5/31/02)

Fastburn 350/340/355 + 5hp to 360 HP

GM LS-1(alum) 350 HP +5 hp to 355 HP

502/502/420 HP +3 hp to 423 HP

1963 426/415/410 (low comp) Max Wedge –5hp to 405 HP

1967-69 Corvette 427/400/385 (oval port, 3 X 2) –10 to 375 HP.

Note: Mopar Performance Cylinder head # 4876311 is an approved part on 440 6-pack combinations. (In. 2.140 Ex. 1.810)

5/7/02

TOP STOCK HP ADJUSTMENTS (effective 5/7/02)

• Fastburn 350/340/345 + 10hp to 355 HP
• GM LS-1(alum) 345 HP +5 hp to 350 HP
• 1966-1970 CHEV 396/375/385 HP +5 hp to 390 HP
• 502/502/415 HP +5 hp to 420 HP

4/25/02

TOP STOCK HP ADJUSTMENTS

• Fastburn 350/335 +10hp to 345 HP

4/3/02

STOCK and SUPER STOCK HP ADJUSTMENTS (effective 4/15/02)

Ford  (Stock)

• 1962-64 260 / 164 HP reduced to 145
• 1965-67 289 / 225 HP reduced to 203
• 1970-71 429 / 375 HP reduced to 355
• 1962-63 406 / 405 HP reduced to 365
• 1963 427 / 425 HP reduced to 385

Ford   (Super Stock)

• 1970-71 429 / 415 HP reduced to 385

Olds / Pontiac

• 1966 67 (Olds 442’s) 400 / 360 HP reduced to 330
• 1970 455 / 365 / 370 HP reduced 350
• 1967-68 Ram Air 1- 400 / 360 and 370 HP reduced to 342
• 1964 389 / 348 HP reduced to 325
• 1965-66 389 / 360 reduced to 335

Chevrolet

• 1961 409 / 360 HP reduced to 325
• 1962 409 / 380 HP reduced to 340
• 1962 409 / 409 HP reduced to 365
• 1963 409 / 340 HP reduced to 306
• 1963-64 409 / 400 HP reduced to 360
• 1963-64 409 / 425 HP reduced to 375

Chevrolet (Super Stock)

• 1965 327 / 250 / 265 HP reduced to 260

1/25/02

TOP STOCK HP ADJUSTMENTS (effective 1/25/02)

· 1966-1970 CHEV 396/375/380 HP +5 hp to 385 HP
· GM LS-1(alum) 340 HP +5 hp to 345 HP
· Camaro / Firebird LT-4 350 at 345 HP

· Fastburn 350/340 -5hp to 335 HP

· 502/502/420 HP -5 hp to 415 HP

· 1967-70 Ram Air 4 Pontiac (1970 engine spec) 400/350 HP

· 360/340 crate -5 hp to 335HP

· 472/525/420 crate hemi – 5 hp to 415 HP

· 351/340 crate –5 hp to 335 HP

· 460/535/420 crate –5 hp to 415 HP

· 428/335/370 CJ (Steel Standard OEM CJ Head) +5 hp to 375 HP

· 428/335/380 CJ (F5 Head) +5 hp to 385 HP
· 1966-67 Fairlane 427/410/415 (med rise) 410 HP

· 1966-67 Fairlane 427/425/440 (med rise - 2 /4 bbl) 420 HP

9/25/01

TOP STOCK HP ADJUSTMENTS (effective 9/25/01)

• 1966-1970 CHEV 396/375/390 HP -10 hp to 38O HP
• 1966-1969 CHEV 427/425/420 HP –10 hp to 410 HP
• 350 GM Fast Burn 350/385/355/345 hp -5 to 340 HP
• GM LS-1(alum) 345 HP -5 hp to 34O HP
• 350 GM LT-1 hp to 340 HP
• 502/502/430 HP –10 hp to 420 HP
• 454/425 (LS6) –10 hp to 410 HP
• 427/470 (ZL-1) to 430 HP
  
• 1970 Stage 2 Buick 395 HP -5 hp to 390 HP
  
• 1963-64 Mopar 426/425/415 hp HI Comp. Max Wedge -5 to 415 HP
• 1966 Mopar 426/425/420 Street Hemi -10hp to 410 HP
• 1967-71 Mopar 426/425/420 Street Hemi -5hp to 415
• 426/415 Max Wedge –5hp to 410HP
• 440/six pack –10 hp to 385 HP
• 472/525 crate hemi – 10 hp to 420 HP
• 360/385/350 crate –10 hp to 340 HP
• 64-65 426 race hemi to 430 hp
  
• 351/385/350 crate –10 hp to 340 HP
• 460/535/430 crate –10 hp to 420 HP
• 428/335/375 CJ (Steel Standard OEM CJ Head) –5 hp to 370 HP
• 428/335/375 CJ (F5 Head) +5 hp to 380 HP

8/28/01

TOP STOCK HP REDUCTIONS (effective 8/28/01)

• 1966-1970 CHEV 396/375/390 HP -5 hp to 385 HP
• 1966-1969 CHEV 427/425 HP -5 hp to 420 HP
• 350 GM Fast Burn 350/385/355 hp -10 to 345 HP
• GM LS-1(alum) -5 hp to 345 HP
• 350 GM Fast Burn 350/385/355 hp -10 to 345 HP
• 1970 Stage 2 Buick -5 HP to 395 HP
• 1963-64 Mopar 426/425 hp HI Comp. Max Wedge -5 to 420 HP
• 1966 Mopar Street Hemi -5hp to 420 HP
• 1966-67 Ford (4V)427/410/415 hp -5 to 410 HP
• 1966-67 Ford (2X4V)427/425/440 hp -15 to 425 HP

6/27/01

Stock HP Adjustments (effective 7/12/01)
("Crate Motor" HP changes)

Chevrolet

• 350 / 300 / 310 hp reduced to 305 hp.
• 350 / 335 hp increased to 340 hp.
• 350 / 355 / 360 hp increased to 365 hp.
• 350 / 385 hp increased to 395 hp.

Mopar

• 360 / 300 / 315 hp (Magnum) increased to 325 hp.
• 360 / 300 / 305 hp (Commando) increased to 315 hp.
• 360 / 360 hp reduced to 350 hp.
• 440 / 410 hp reduced to 405 hp.

6/6/01

Super Stock HP Adjustments
1972 Buick 455 / 315 hp reduced to 300.

Stock HP Adjustments
1970 Olds 455 / 375 hp reduced to 365.

4/26/01

Stock and Top Stock HP Adjustments

Pontiac Firebirds (Ram Air 1,2,3&4)

• '67 400 / 360 reduced to 342
• '68 400 / 370 reduced to 352
• '69 400 / 375 reduced to 356
• '70 400 / 380 reduced to 361

Top Stock HP Adjustments

• Reduce accepted Big Block crate combinations to 430 HP.
• Reduce accepted Small Block Chevrolet and Mopar combinations to 355 hp.
• Reduce accepted Small Block Ford crate combo to 350 hp.

2/26/01

Chevrolet Crate Motor
350/345 should read 355 hp for factored horsepower

6/27/00

HP Adjustments (adjustments are for Stock and Super Stock)

• 1970 Chevrolet 350 / 370 hp reduced to 351.
• 1966-69 AMC 290 / 225 hp reduced to 214.
• 1973-74 Pontiac 455 / 290/350 hp reduced to 332.
• 1972 Pontiac 455 / 300/350 hp reduced to 332.

5/1/00

Stock Eliminator HP Adjustments

( "Crate Motor" HP changes)
Chevrolet

• 350 / 330 hp increased to 340 hp.

Mopar

• 360 / 300/310 hp (Magnum) increased to 315 hp.
• 360 / 300 hp (Commando) increased to 305 hp.
• 360 / 380 hp reduced to 370 hp.

(Stock Eliminator)
Ford

• 1986 302 / 200/210 hp reduced to 205.

The minimum cylinder head volume for the 360 / 300 Commando combination has been reduced from 70.2 to 64.7 cc. Based upon this change the hp has been increased from 300 to 305.

1/25/00

Stock Eliminator HP Adjustments

Ford "Crate Motor" HP Reductions

• 302 / 270 hp reduced to 250 hp.
• 302 / 285 hp reduced to 265 hp.
• 302 / 320 hp reduced to 300 hp.
• 351 / 385 hp reduced to 375 hp.
• 351 / 362 hp reduced to 352 hp.